In 1248, a civil war broke out between Mindaugas and his nephews Tautvilas and Edivydas. The powerful coalition against Mindaugas included Vykintas, the Livonian Order, Daniel of Galicia and Vasilko of Volhynia. Taking advantage of internal conflicts, Mindaugas allied with the Livonian Order. He promised to convert to Christianity and to exchange some lands in western Lithuania in return for military assistance against his nephews and the royal crown. In 1251, Mindaugas was baptized and Pope Innocent IV issued a papal bull proclaiming the creation of the Kingdom of Lithuania. After the civil war ended, Mindaugas was crowned as King of Lithuania on 6 July 1253, starting a decade of relative peace. Mindaugas later renounced Christianity and converted back to paganism. Mindaugas tried to expand his influence in Polatsk, a major centre of commerce in the Daugava River basin, and Pinsk. The Teutonic Knights used this period to strengthen their position in parts of Samogitia and Livonia, but they lost the Battle of Skuodas in 1259 and the Battle of Durbe in 1260. This encouraged the conquered Semigallians and Old Prussians to rebel against the Knights.