Complex sentence: He changed his name to Clément-Bayard 5 years after the successful launch of the "Clément-Bayard" automobile brand, to honour the Chevalier Pierre Terrail, seigneur de Bayard who saved the town of Mézières from the English invaders in 1521.
Split into simpler sentences: He changed his name to Clément-Bayard 5 years after the successful launch of the "Clément-Bayard" automobile brand. It honoured the Chevalier Pierre Terrail, seigneur de Bayard who saved the town of Mézières from the English invaders in 1521.