Complex sentence: Henry's escape from the duties of court is foiled when he encounters a band of gypsies robbing an old man, and when he learns that the old man is Leonardo da Vinci, who has been summoned to court, he decides to return with him.
Split into simpler sentences: Henry's escape from the duties of court is foiled when he encounters a band of gypsies robbing an old man. He learns that the old man is Leonardo da Vinci, who has been summoned to court, then returns with him.