Complex sentence: In 1207 he was in the Rhone valley and in Provence, where he became involved in the strife between the count of Baux and Raymond, count of Toulouse, was assassinated on 15 January 1208, quite possibly by an agent of Raymond.
Split into simpler sentences: In 1207 he was in the Rhone valley and in Provence, where he became involved in the strife between the count of Baux and Raymond, count of Toulouse. Castelnau was assassinated on 15 January 1208, quite possibly by an agent of Raymond.