Complex sentence: In response to the defeat, Pope Innocent III issued a papal bull declaring a crusade against the mostly-pagan Livonians, who were conquered and converted between 1202 and 1209.
Split into simpler sentences: In response to the defeat, Pope Innocent III issued a papal bull declaring a crusade against the mostly-pagan Livonians. The Livonians were conquered and converted between 1202 and 1209.