Osman I, Ottoman Founder: What the Sources Say
Who Osman I was in the sources that name him, what a Byzantine historian and two deeds record, and when the famous stories were first written down.
Table of Contents
Osman I gave his name to the Ottoman dynasty. What can be said about him depends on when each source was written. A Byzantine historian and two deeds come from his own time, two writers of the 1330s add a little, and the best-known stories were written down 80 to 175 years after he died.
The short version
Named in 1302, 1323 and 1324,
and told again from the 1400s.
- Who: a frontier leader (an alp, a gazi) in the Söğüt and Bilecik country of north-west Anatolia, named as Ertuğrul’s son in the deed of 1323.
- In his own time: the Byzantine historian Pachymeres names him at the battle of Bapheus on 27 July 1302. Two deeds show him alive in September 1323 and gone by March 1324.
- Told later: Ertuğrul’s story, the Kayı descent, the dream and the silver dome first appear in chronicles written from the early 1400s to about 1500.
- The date 1299: the traditional date for the state’s beginning. The first date from a source of his own time is Bapheus, 27 July 1302.
- Titles: İbn Battûta, in the 1330s, writes “Sultan Osmancık”. An inscription of 1337 calls his son Orhan “sultan of the ghazis”.
The map
Where Osman’s men were, stage by stage
- Held by Osman or Orhan
- Byzantine town
- Under siege
- Area, position approximate
- Where his men ranged
1284
Söğüt, the frontier town
Told later in the chronicles
Söğüt is the last town on the Seljuk side, and the Byzantine border starts at Bilecik. The local lords between the two accept the Seljuk sultan and live at peace with the Turkmen. Families winter in the villages and take their flocks up to the Domaniç pastures in summer.
- Osman’s raiding begins with the taking of Kulaca, in 1284.
TDV Osman I
1288
Karacahisar
Told later in the chronicles
Osman takes the fort of Karacahisar from the lord who paid tribute to the Seljuk sultan. Turkmen risings against the Seljuks and the Mongols gave him the chance.
- Karacahisar is his base from 1288 to about 1299.
TDV Osman I
About 1299
Bilecik and Yenişehir
Told later in the chronicles
Osman now holds a wide country, from Eskişehir to Bilecik and Yenişehir. He settles at Yenişehir, leaves his family at Bilecik and turns towards İznik.
- İnönü goes to his son Orhan, Yarhisar to Hasan Alp, İnegöl to Turgut Alp.
TDV Osman I
27 July 1302
Bapheus
A Byzantine historian of the time
Osman’s men are besieging İznik. A Byzantine force comes to relieve it, and the two sides meet at Yalakova, where the Yalakdere valley reaches the plain. The Turks are the larger side and win.
- The counts are Pachymeres’. The Byzantine commander is Léon Mouzalôn.
- The Byzantines flee towards İzmit. Raiding reaches Bursa and İznik, and warriors from as far as Paphlagonia join him.
TDV Osman I · Pachymeres
1303
Dimbos and Kite
Told later in the chronicles
After Bapheus the lords of the Bursa plain unite against him. Osman beats them on the Yenişehir plain and again in the narrow Dimbos pass. The lord of Kestel dies there, and so does Osman’s nephew Aydoğdu.
- The lord of Kite is chased to the Ulubat bridge and handed over; when he is put to death, Kite fort gives in.
- Uludağ and the plain open to Turkmen settlers. Two towers, Aktimur and Balabancık, cut Bursa off for 23 years.
TDV Osman I
1304
The Sakarya crossings
Told later in the chroniclesA Byzantine historian of the time
To cut İznik off from help, Osman marches on the Sakarya crossings. Leblebüci fort, Lefke and Çadırlı submit and become his companions (nöker). Mekece submits too, and the lord of Akhisar is beaten. Osman takes Geyve and Tekfurpınarı and stays a month.
- Karaçepüş holds out; Orhan is sent against it the next year.
- Panic in Constantinople: raiders are seen as far as the Bosphorus.
TDV Osman I · Pachymeres
September 1323 to March 1324
Two deeds, and Orhan
A document of his own time
In September 1323 Osman is alive. In March 1324 Orhan holds the lordship. Osman died between the two dates.
- Orhan’s last campaign in his father’s time is against Adranos fort (Orhaneli).
- Osman’s vizier in his last years is Alâeddin Paşa, named in the deed of 1323.
TDV Orhan · Mal Hatun · Osman I
6 April 1326
Bursa gives itself up
Told later in the chronicles
Osman has died. In spring 1326 his son Orhan comes before Bursa with all his force and asks the city to surrender.
- No plunder and no captives.
- Those who wish may leave with their goods.
- The city pays Orhan 30,000 gold.
TDV Orhan · Osman Gazi Türbesi
1329 to 1331
Pelekanon and İznik
A Byzantine historian of the time
Emperor Andronikos III crosses the sea to relieve İznik. On 1 and 2 June 1329 his army meets Orhan’s at Pelekanon and breaks. The emperor, wounded in the leg by an arrow, is carried onto a ship on a carpet.
- Orhan takes all of Kocaeli.
- İznik gives in on 2 March 1331 (İbn Kemal gives 1333).
TDV Orhan
What each stamp rests on
- A document of his own timeWritten while Osman or his son Orhan was alive.
- A Byzantine historian of the timeWritten by a Byzantine author of the same years.
- Told later in the chroniclesTold in chronicles put down long after his death.
Coast: Natural Earth (public domain). The shaded reach joins the places named on the cards; it is not a border.
In his own lifetime, five records
Few records come from Osman’s own years. A Byzantine historian named him at the battle of Bapheus on 27 July 1302. Two deeds show him alive in September 1323 and gone by March 1324. Two writers of the 1330s add a line each.
Written then
Five records, in date order
In his lifetime
about 1307
Georgios Pachymeres
Names Osman (as Atmanes) at Bapheus on 27 July 1302: a frontier raid leader, the boldest of several, who began as a border fighter under the Çobanoğulları of Kastamonu.
In his lifetime
early September 1323
Asporça Hatun deed
Orhan’s wife endows two villages that Osman had given her, with Alâeddin Paşa as her agent. Osman is alive, and named as Ertuğrul’s son.
In his lifetime
8 to 18 March 1324
Mekece deed
Lists Osman’s sons, a daughter and three women as witnesses. Osman is gone and Orhan holds the lordship.
Under 10 years later
1330
Âşık Paşa, Garibnâme
Describes the frontier captains (subaşı, alp gazi) of Osman’s kind.
Under 10 years later
the 1330s
İbn Battûta
Writes the name Osmancık, calls Orhan his son and names his tomb at Bursa.
Pachymeres does not describe a sultan. He describes a border fighter in the service of the Çobanoğulları, the frontier lords of Kastamonu. When the raids of a rival leader stopped, his men came over to Osman, and the raiding went on under Osman’s lead.
Two deeds, and the people beside the page
The Asporça Hatun deed of early September 1323 is the most important document of Osman’s time. Orhan’s wife Asporça Hatun endows two villages that Osman had given her and names Alâeddin Paşa as her agent. The Mekece deed of 8 to 18 March 1324 is one of the earliest surviving documents of Ottoman history.
The Mekece deed
Who stood beside the page
In mid Rebîülevvel 724, which is 8 to 18 March 1324, witnesses stood for an endowment at Mekece. Tap a line to see what the deed says, and what the chronicles say around it.
Mekece deed · mid Rebîülevvel 7248–18 March 1324
Witnesses, in the order of the list
- Çoban, Melik, Hâmid, Pazarlısons of Osman
- Fatmadaughter of Osman
- Mal Hatun bint Ömer Beydaughter of Ömer Bey
- Melek bint Melik · Efendire bint Akbaşlıdaughters of Melik and of Akbaşlı
Çoban, Melik, Hâmid and Pazarlı
The deed Four sons of Osman are named, besides Orhan. They open the list of witnesses.
Around it The chronicles add another son, Alâeddin Ali; the Bursa tomb holds a sarcophagus known to be his. The name Çoban may link to the Ilkhanid emir of that name.
TDV Mal Hatun · Osman I · Osman Gazi Türbesi
Fatma
The deed Osman’s daughter Fatma is named, straight after his sons.
Around it The sons and the daughter are listed first. Three women follow straight after them.
TDV Mal Hatun
Mal Hatun, daughter of Ömer Bey
The deed She is named first of the three women, and the deed gives her father as Ömer Bey. She is alive in March 1324, after Osman’s death.
Around it Âşıkpaşazâde, 1484, calls her Malhun Hatun, Edebâli’s daughter, and has her die before Osman. Oruç calls the sheikh’s daughter Râbia; Neşrî names no father. It is certain she was not Edebâli’s daughter and likely, but not certain, that she was Orhan’s mother. Who Ömer Bey was is not settled.
Melek and Efendire
The deed Two more women stand as witnesses: Melek, daughter of Melik, and Efendire, daughter of Akbaşlı.
Around it These two and Mal Hatun are discussed as possible wives of Osman or of Orhan; the deed does not say.
TDV Mal Hatun
The two deeds are the firmest anchors for the end of Osman’s life. He is alive in September 1323; by March 1324 Orhan holds the lordship. Osman died in between. Neither deed gives his age. His birth is put at 1257 or 1258, worked out from a chronicle count (dead at 69 after 27 years of rule); neither date comes from a document.
Söğüt and the frontier, a country of captains
Söğüt was a frontier town where Seljuk land met Byzantine land, north-west of Eskişehir. Turkmen families lived in the villages and took their flocks up to the Domaniç summer pastures. Captains known as alp organised the raids. Osman was an alp gazi of that kind. He gathered Turkmen and refugees (garip) for the frontier war. He was not a plain shepherd.
Söğüt
Ertuğrul’s tomb: from an open grave to a restored tomb
Hexagonal
A domed hexagon, entered through a rectangular porch.
Late 1200s
Osman has an open grave made for his father. The exact date is not known.
Mehmed I Çelebi
The open grave becomes a tomb.
1757
Sultan Mustafa III has the tomb restored.
1886
Sultan Abdülhamid II has it restored again. Two fountains are added at the entrance during these repairs.
Around the tomb: Ertuğrul’s wife Halime Hatun, his son Savcı Bey, a memorial grave of Osman, and the graves of companions such as Konur Alp, Akçakoca and Aktimur Bey.
Two men of learning stood close to Osman: Sheikh Edebâli of Bilecik and the jurist Dursun Fakih, Edebâli’s son-in-law. Osman visited Edebâli’s lodge on holy days to ask his view on religious and practical questions. Edebâli led the ahi brotherhood and was the first Ottoman judge (kadı) and mufti. He died in 1326 and lies in the lodge with his wife, his daughter and others.
The land registers show endowments to jurists and ahis already under Osman. In his last years his vizier was Alâeddin Paşa, the agent named in the deed of 1323.
The stories, and what historians make of them
The tree of the dream
When was each story first written down?
In the chronicle, Osman dreams of a tree that grows from his navel and shades the world. Here the tree stands for the sources. The documents of his own time are the roots, two writers of the 1330s ring the trunk, and the stories told later hang in the crown, higher the later they were written down. Tap a leaf to see who first wrote it, and what a document or a historian says.
- Written at the time
- Told in a later chronicle
- A document says otherwise
Written in his lifetime
Bapheus, as a Byzantine historian wrote it
Osman leads a force against a Byzantine army near Nicomedia and wins.
Source Georgios Pachymeres, born at Nicaea in 1242. His history covers 1260 to 1307. He is the first historian to name Osman (as Atmanes), at Bapheus on 27 July 1302.
What it shows Osman as the boldest raid leader among the Turkmen of that frontier, a border fighter tied to the Çobanoğulları of Kastamonu. The Byzantine force under Léon Mouzalôn numbered about 2,000 and the Turks about 5,000. After the victory Osman’s fame spread to Paphlagonia and warriors gathered under his banner. İnalcık: 27 July 1302 can be accepted as the date the dynasty began.
TDV Pachymeres · Osman I
Written in his lifetime
Two deeds around his last year
Two endowment deeds, about six months apart.
Source The Asporça Hatun deed (early Ramazan 723, early September 1323) and the Mekece deed (mid Rebîülevvel 724, 8 to 18 March 1324).
What they show In the first, Osman is alive: Orhan is named as the son of Osman Gazi, son of Ertuğrul. In the second, Osman is gone and Orhan holds the lordship. So Osman died between the two dates. No source gives his birth: a chronicle count (aged 69, after 27 years of rule) works out at 1257.
Written within ten years
Two voices from the 1330s
Two writers of the 1330s mention Osman, or lords like him.
Source Âşık Paşa’s Garibnâme of 1330 describes the frontier captains (subaşı, alp gazi) that Osman belonged to. İbn Battûta, born in 1304, crossed Bursa and İznik and writes the name as Osmancık.
What they show İbn Battûta describes the respected place of the Ottomans among the neighbouring principalities and calls Orhan the son of “Sultan Osmancık”. Neither he nor Pachymeres, Kantakuzenos, Gregoras or al-ʿUmarî names Ertuğrul.
TDV Osman I · İbn Battûta · Ertuğrul Gazi
Told in a later chronicle
Ertuğrul and the Seljuk sultan
Ertuğrul comes to the Söğüt frontier, helps the Seljuk sultan Alâeddin in a battle, and is given land.
First written down The first Ottoman chronicles, from the early 1400s, some 80 years after Osman died. They give his father’s name as Gündüz Alp (Ahmedî, Enverî, Karamânî Mehmed Paşa) or Süleyman Şah (Oruç, Âşıkpaşazâde, Neşrî).
What the documents and historians say The deed of 1323 already names Osman as Ertuğrul’s son. A later land register lists a farm at Söğüt endowed “for Ertuğrul’s soul”, the earliest record about him. İnalcık reads the tale of help to the sultan as a faint memory of the Seljuk and Nicaean wars of 1225 to 1231.
TDV Ertuğrul Gazi · Osman I
Told in a later chronicle
Descent from the Kayı tribe
Osman’s line runs back through the Kayı tribe to Gün Han, son of Oğuz Khan.
First written down in full Yazıcıoğlu Ali, in his Târîh-i Âl-i Selçûk, 1436–37, about 112 years after Osman’s death. It answered the pressure that Timur’s son Şâhruh put on the Ottoman court.
What historians say Wittek held that the descent was a later dynastic claim, made in Murad II’s time. Köprülü took the Kayı as the first ethnic core of the state. The sources agree that Osman’s tribe was of Oğuz (Turkmen) stock. The Kayı link is probably Yazıcıoğlu’s idea but may be right. Murad II was the first Ottoman ruler to stamp the Kayı mark on his coins.
Told in a later chronicle
The frontier lords ask him to be han
Border lords gather at Osman’s door, talk long, and ask him to be their han. He accepts.
First written down Yazıcıoğlu Ali, 1436–37: “siz han olun”, “you be khan”, say the lords.
What historians say İnalcık places the Anatolian beys’ own declarations of sultanate, with the Friday sermon and coin in their name, in 1335, after the last Ilkhan had died. The scene sits beside the later claim that Osman had the sermon read in his name.
TDV Osman I
Told in a later chronicle
The dream at Edebâli’s lodge
Osman sleeps at Sheikh Edebâli’s lodge in Bilecik. A moon rises from the sheikh’s chest and enters his. A tree grows from his navel; its shade covers the world, mountains rise beneath it, and rivers flow from each. Edebâli says: “God has given you and your line sovereignty. May it be blessed.”
First written down Âşıkpaşazâde, who finished his history in 1484, about 160 years after Osman’s death. His sources are Yahşi Fakih, son of the imam İshak Fakih, and Mahmud Paşa, Edebâli’s son.
What historians say İnalcık holds that Yahşi Fakih’s lost life of the early beys is Âşıkpaşazâde’s main source, and that its place names and routes check out. He reads blessing stories like this one, told of many Turkmen lords, as a way of showing that a ruler’s authority was divinely confirmed.
TDV Edebâli · Osman I · Âşıkpaşazâde
Told later; a document says otherwise
Mal Hatun, daughter of Edebâli
Osman marries Malhun Hatun, Sheikh Edebâli’s daughter. She is Orhan’s mother.
First written down Âşıkpaşazâde, 1484, about 160 years after Osman’s death.
What a document says The Mekece deed of March 1324 names her Mal Hatun, daughter of Ömer Bey. It is certain she was not Edebâli’s daughter, and likely, though not certain, that she was Orhan’s mother. Oruç gives the sheikh’s daughter the name Râbia; Neşrî tells of a youthful meeting in the village of İtburnu and names no father.
Told later; a document says otherwise
Edebâli and Mal Hatun die, and Osman buries them
Edebâli and Mal Hatun die a month or two apart. Osman, who dies three months later, buries both with his own hands at Bilecik.
First written down Âşıkpaşazâde, 1484, about 160 years after Osman’s death.
What a document says Mal Hatun is a witness in the Mekece deed of March 1324, after Osman’s death, so she outlived him. Edebâli died in 1326 (one source says 1327).
Told in a later chronicle
The silver dome at Bursa
During the long siege of Bursa, Osman looks at the city from its walls, sees a monastery chapel gleaming like silver, and asks to be buried under that dome.
First written down Âşıkpaşazâde, 1484.
What is known Bursa surrendered on 6 April 1326, so the burial there came after it. Orhan buried his father in the round chapel. İbn Battûta, in the 1330s, already names Osman’s tomb inside a mosque that had been a church. The building burned in 1801 and the earthquake of 1855 damaged it badly; the present tomb dates from 1863.
TDV Osman Gazi Türbesi · Orhan
Told in a later chronicle
The sermon read in his name
Osman declares himself an independent lord: the Friday sermon (khutba) is read in his name.
First written down Âşıkpaşazâde (chapter 14), at Karacahisar. Neşrî, who wrote between about 1485 and 1493, puts it after the death of the Seljuk sultan Alâeddin.
What historians say İnalcık: the arguments for independence in Âşıkpaşazâde were added much later by people who believed the dynasty began with Osman. The Mongols took the Seljuk sultan Alâeddin III to Tabriz in 1302, the last Seljuk ruler held on until 1308, and the Anatolian beys took sermon and coin only in 1335.
Told in a later chronicle
Ertuğrul’s dream, and Râbia
The dream is Ertuğrul’s, not Osman’s, and the sheikh’s daughter who marries Osman is called Râbia.
First written down Oruç b. Âdil, in his Tevârîh-i Âl-i Osmân, in a text of about 1495 and a longer one of 1500–03, about 175 years after Osman’s death.
What historians say Oruç kept this version although he knew Âşıkpaşazâde’s book. İnalcık’s advice is to read the opening sections of the chronicles with care, separating vague claims from the historical information they carry.
TDV Edebâli · Mal Hatun · Oruç b. Âdil
Years are counted from 1324, when the deeds show that Osman had died.
The historians
How much weight can the chronicles carry?
Four readings of the chronicle layer
Little weightMuch weight
- 1
Imber
Has called the early period a “black hole”.
- 2
Wittek
Read the Kayı descent as a later dynastic claim and proposed the “ghaza thesis”: warriors for the faith as the core of the early state. Lindner and others criticise it.
- 3
İnalcık
Answers that dismissing the chronicles wholesale as tales is the easy way out: their place names and routes check out, and Pachymeres supplies detail they lack.
- 4
Köprülü
Defended the Kayı as the state’s first ethnic core.
How the stories travelled
İshak Fakih
a contemporary of the first beys
Handed his accounts to his son.
Yahşi Fakih
his son
Wrote a life of the first beys. It has not survived.
Âşıkpaşazâde
finished 1484, about 160 years after Osman
Names Yahşi Fakih and Mahmud Paşa, Edebâli’s son, as his sources.
Neşrî, Oruç and others
chronicles of the 1400s
Draw on the same book.
1299
The traditional date
The old chronicle story dates Osman’s taking of Bilecik, and his independence, to this year. It falls in a time of Mongol unrest in Anatolia.
27 July 1302
Bapheus
The first dated action in a source of his own time. İnalcık: it can be accepted as the beginning of the dynasty.
Both dates are in use. Which one a book gives depends on whether it follows the chronicles or Pachymeres.
Bursa and İznik, cut off for years
Osman did not live to see Bursa fall. After the battles of 1303 he cut the city off with two small forts, and the siege lasted 23 years. His son Orhan took Bursa on 6 April 1326. İznik followed on 2 March 1331.
The siege
Bursa, cut off for 23 years
Other accounts say 20 to 25 years.
6 April 1326
- 1
In spring 1326 Orhan comes before Bursa with all his force and asks the city to give itself up.
- 2
No plunder and no captives: the soldiers who enter will not harm the people.
- 3
Those who wish may leave with their goods, under the protection of Orhan’s soldiers.
On surrender
30,000 gold
paid to Orhan.
İznik held out longer. Emperor Andronikos III crossed the sea to relieve it, and on 1 and 2 June 1329 his army broke at Pelekanon. Wounded in the leg, he was carried onto a ship on a carpet. Two years later İznik gave in.
Where he lies, and what he looked like
Osman lies in Bursa, in the tomb at Tophane on the hill of the old citadel. The tomb seen today was built in 1863. It stands where a round Byzantine building, the “Silver Dome” (Gümüşlü Kümbet), once stood. The chronicles say Orhan buried his father there after taking the city.
The tomb
The tomb of 1863, and who lies in it
7 windows
Eight sides: a door on one, a window on each of the other seven.
1863
Rebuilt for Sultan Abdülaziz after the fire of 1801 and the earthquake of 1855.
17 sarcophagi
Five have a known owner. The other twelve do not.
UNESCO 2014
The tomb lies inside the World Heritage site “Bursa and Cumalıkızık: the birth of the Ottoman Empire”.
- 1
The porch
Two slender columns carry Sultan Abdülaziz’s tuğra (his seal).
- 2
The entrance hall
Wooden arches. The türbedar’s room lies on the west side.
- 3
The tomb
An octagonal chamber under a dome, with a ten-line inscription by Osman Nevres dated 1280 (1863).
- 4
Osman’s sarcophagus
At the centre: wood inlaid with mother-of-pearl, a railing round it, a velvet cover worked in metal thread. Cover and latticework were restored in 2004.
17 sarcophagi, five with a known owner
Tap a gold tile. The tiles do not show where each one stands.
Osman Gazi
At the centre of the tomb, under the velvet cover.
Alâeddin Bey
Osman’s son. The chronicles call him Alâeddin Ali.
Asporça Hatun
Orhan’s wife. Her deed of September 1323 shows Osman alive.
İbrâhim
Orhan’s son, born to Asporça.
Savcı Bey
Murad I’s son.
Three faces, none from life
Was he a sultan? The coin and the sermon
A sultan has his name read in the Friday sermon and struck on coins. İbn Battûta, in the 1330s, writes “Sultan Osmancık”. But no Turkmen bey in Anatolia took the title “greatest sultan” before 1335, when the last Ilkhan had died. An inscription of 1337 calls Orhan “sultan of the ghazis”. The silver coin shown here was struck in Orhan’s time.
Quick answers
Was Osman I a sultan?
The sources use different words. Pachymeres writes of a frontier raid leader. İbn Battûta, in the 1330s, writes “Sultan Osmancık”. No Turkmen bey in Anatolia took the title “greatest sultan” before 1335, and an inscription of 1337 calls his son Orhan “sultan of the ghazis”. Later Ottoman tradition counts Osman as the first of the line.
When did the Ottoman state begin?
The traditional date is 1299, from the old chronicle story. İnalcık reads Bapheus, 27 July 1302, the first date from a source of Osman’s own time, as a date that can be accepted for the beginning of the dynasty. Both dates are in use.
Was Mal Hatun the daughter of Sheikh Edebâli?
Âşıkpaşazâde says so, in 1484. The Mekece deed of March 1324 names her as the daughter of Ömer Bey, and it is certain she was not Edebâli’s daughter.
What did Osman look like?
No likeness made in his lifetime is known. Three well-known faces were made at least 225 years after his death: the miniature of 1579/80, a painting from the circle of Paolo Veronese, and Laurence Johnson’s engraving of 1603 for Knolles’s history of the Turks.
Where is Osman buried?
In Bursa, in the tomb at Tophane that Sultan Abdülaziz had built in 1863. His son Orhan’s tomb is beside it. A memorial grave (makam) for Osman also stands at Söğüt, outside Ertuğrul’s tomb.
Sources
Open the source list
- Osman I, Halil İnalcık — TDV İslâm Ansiklopedisi, printed 2007, checked 20.10.2026
- Orhan, Halil İnalcık — TDV İslâm Ansiklopedisi, printed 2007, checked 20.10.2026
- Mal Hatun, Feridun Emecen — TDV İslâm Ansiklopedisi, printed 2019, checked 20.10.2026
- Edebâli, Kamil Şahin — TDV İslâm Ansiklopedisi, printed 1994, checked 20.10.2026
- Ertuğrul Gazi, Fahameddin Başar — TDV İslâm Ansiklopedisi, printed 1995, checked 20.10.2026
- Kayı, Faruk Sümer — TDV İslâm Ansiklopedisi, printed 2022, checked 20.10.2026
- Pachymeres, Georgios, Levent Kayapınar — TDV İslâm Ansiklopedisi, printed 2007, checked 20.10.2026
- Âşıkpaşazâde, Abdülkadir Özcan — TDV İslâm Ansiklopedisi, printed 1991, checked 20.10.2026
- Neşrî, Abdülkadir Özcan — TDV İslâm Ansiklopedisi, printed 2007, checked 20.10.2026
- Oruç b. Âdil, Abdülkadir Özcan — TDV İslâm Ansiklopedisi, printed 2007, checked 20.10.2026
- Wittek, Paul, Turgut Akpınar — TDV İslâm Ansiklopedisi, printed 2013, checked 20.10.2026
- İbn Battûta, A. Said Aykut — TDV İslâm Ansiklopedisi, printed 1999, checked 20.10.2026
- Osman Gazi Türbesi, Doğan Yavaş — TDV İslâm Ansiklopedisi, printed 2007, checked 20.10.2026
- Osman Gazi Türbesi – Bursa — Kültür Portalı, Ministry of Culture and Tourism, kulturportali.gov.tr, checked 23.10.2026
- Ertuğrul Gazi Türbesi – Bilecik — Kültür Portalı, Ministry of Culture and Tourism (text of the Bilecik provincial directorate), kulturportali.gov.tr, checked 23.10.2026
- Şeyh Edebali Türbesi – Bilecik — Kültür Portalı, Ministry of Culture and Tourism, kulturportali.gov.tr, checked 23.10.2026
- Portret van sultan Osman I (RP-P-1905-4914) — Rijksmuseum, engraving by Laurence Johnson for Richard Knolles’s history of the Turks, published in London by Adam Islip, 1603, Public Domain, checked 20.10.2026
- Türbeler — Bursa Provincial Directorate of Culture and Tourism, bursa.ktb.gov.tr, checked 20.10.2026
- Vakıflar Genel Müdürlüğü Arşiv Rehberi — Directorate General of Foundations, cdn.vgm.gov.tr, entry Asporçe Hatun (723 / 1323), checked 20.10.2026
