Complex sentence: Although Sancho II's troops were victorious, he decided not to persecute his brother Alfonso who was imprisoned in Burgos, and later transferred to the monastery of Sahagún, where his head was shaved and he was forced to wear a chasuble.
Split into simpler sentences: Although Sancho II's troops were victorious, he decided not to persecute his brother Alfonso who was imprisoned in Burgos. Later he was transferred to the monastery of Sahagún, where his head was shaved and he was forced wear a chasuble.