help Esen Buqa. 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. The Khan's diplomatic relationship with the Yuan, however, improved in 1324. Ayurbarwada Buyantu Khan granted him the de jure rights to rule the Golden Horde (Ulus of Jochi in the Yuan sources). 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. Öz Beg was engaged in wars with Bulgaria and the Byzantine Empire from 1320 to 1332. He repeatedly raided Thrace, partly in service of tsar Michael Shishman of Bulgaria war against both Byzantium and Serbia that began in 1319. His armies pillaged Thrace for 40 days in 1324 and for 15 days in 1337, taking 300,000 captives. After Öz Beg's death in 1341, his successors did not continue his aggressive policy and contact with Bulgaria lapsed. His attempt to reassert Mongol control over Serbia was unsuccessful in 1330. Byzantine Emperor Andronikos III purportedly gave his illegitimate daughter in marriage to Öz Beg but relations turned sour at the end of Andronikos's reign, and the Mongols mounted raids on Thrace between 1320 and 1324 until the Byzantine port of Vicina Macaria was occupied by the Mongols. Andronikos's daughter, who adopted the name Bayalun, managed to escape back to the Byzantine Empire, apparently fearing her forced conversion to Islam. In the south-east of the Kingdom of Hungary, Wallachia and its ruler Basarab I became an independent power with the support of Öz Beg after 1324. Öz Beg allowed Genoese merchants and mariners, who had been harassed by Tokhta, to settle in Crimea. But the Mongols sacked Sudak under Khan Öz Beg in 1322 as a result of a clash between Christians and Muslims in the city. The Genoese merchants in the other towns were not molested in 1322. 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. Öz Beg was friendly towards the Pope and exchanged letters and gifts. Khan Öz Beg signed a new trade treaty with the Genoese in 1339 and allowed them to rebuild the walls of Caffa. In 1332