Toqta took Togrilcha's widow for wife and sent his son Öz Beg to exile in a distant region of the Golden Horde: either Khorazm or the country of Circassians.

Converted to Islam by Ibn Abdul Hamid, a Sunni Sufi Bukharan sayyid and sheikh of the Yasavi order, Öz Beg assumed the throne upon the death of his uncle Toqta in January 1313 with the help of the former Khans' vizier Temur Qutlugh and of Bulaghan (or Bayalun) khatun.

Öz Beg determinedly spread Islam among the Golden Horde and allowed missionary activities to expand in the surrounding regions.

Öz Beg found out that his competitor was backed by the envoys of the Great Khan Ayurbarwada Buyantu and this fact helped deteriorate his relationship with the Yuan dynasty.

In the long run, Islam enabled the Khan to eliminate inter-factional struggles in the Horde and to stabilize state institutions.

Nevertheless, remembering their support for the rival claimant to his throne, Öz Beg tried his best to eliminate every influence and inspiration of the Yuan dynasty on the Golden Horde in the early part of his reign.

[9] Ayurbarwada Buyantu Khan granted him the de jure rights to rule the Golden Horde (Ulus of Jochi in the Yuan sources).

[10] By the 1330s, Öz Beg had begun sending tribute to the Mongol Yuan Emperors and received his share from Jochid possessions in China and Mongolia in exchange.

He repeatedly raided Thrace, partly in service of tsar Michael Shishman of Bulgaria war against both Byzantium and Serbia that began in 1319.

Andronikos's daughter, who adopted the name Bayalun, managed to escape back to the Byzantine Empire, apparently fearing her forced conversion to Islam.

The Pope himself intervened and asked Öz Beg to restore the Roman Catholic churches that were destroyed in revenge, because of the Christian clash against Muslims in the city.

The accretion of the dwellings in the region transformed the capital into the center of a large Muslim government, giving it the appropriate aspect and status.

When the Khan's cousin, the baskak Shevkal, and his Tatars were killed in Tver and a rebellion erupted there in mid-August 1327, Dmitry's successor as Prince of Tver and Grand Prince of Vladimir-Suzdal, his brother Alexander Mikhailovich, fled first to Novgorod—which turned him away—and then to Pskov—which made him its Prince—in order to escape a punitive expedition of 50,000 Mongol-Tatars and Muscovites, which was headed by his cousin, Yury's brother and successor Ivan Daniilovich.

Öz Beg appointed Ivan to position of Grand Duke of Vladimir in 1332; that marked the true beginning of the rise of the Muscovites.

He sent his son Fyodor to the Horde, with tribute and seeking forgiveness, in 1335; the Khan pardoned Alexander and he was given the princely yarlik to Tver once again in 1337.

Wives: Sons: Daughters: Many Arab and Persian authors of the 14th–15th centuries described Öz Beg Khan as an able statesman and a good-hearted, caring person.

Historian al-Mufaddal described him as a young man of good appearance, excellent character, a fine Muslim, brave and energetic.

Geographer and historian Al-Ayni wrote: "He was a brave and courageous man, religious and pious, revered jurists, loved scientists, listened to them, trusted them, was merciful to them, visited the sheikhs and did good deeds to them.

Turkmen historian Adh-Dhahabi speaks of him in the same manner: "... a brave hero, handsome in appearance, a Muslim, who destroyed many emirs and wizards."

[34] According to Rashid al-Din Hamadani, the last representative of the Ildegizid Turkic dynasty, who ruled in Tabriz, was called Öz Beg Muzaffar (1210–1225).