Complex sentence: According to one of Becket's correspondents, Henry was knighted by his father before the coronation, but the biographer of William Marshal asserts that the king was knighted by William in the course of the rebellion of 1173.
Split into simpler sentences: According to one of Becket's correspondents Henry was knighted by his father before the coronation. But the biographer of William Marshal asserts that the king was knighted by William in the course of the rebellion of 1173.