Complex sentence: During his life Baldwin expanded his territory into one of the major principalities of Western Francia, he died in 879 and was buried in the Abbey of St-Bertin, near Saint-Omer.
Split into simpler sentences: During his life, Baldwin expanded his territory into one of the major principalities of Western Francia. He died in 879 and was buried in the Abbey of St-Bertin, near Saint-Omer.