The Livonian Brothers of the Sword, a crusading military order established in 1202, set out to conquer and convert to Christianity indigenous peoples of present-day Latvia and Estonia. They subjugated the Semigallians by 1250. However, after the Livonian defeats in the 1259 Battle of Skuodas and the 1260 Battle of Durbe, the Semigallians rebelled. Traidenis, who became Grand Duke of Lithuania in 1269 or 1270, supported the rebellion.