Complex sentence: Cosme Damián de Churruca an officer of the Spanish Navy, performed heroically in a siege of Gibraltar, and he commanded the 74-gun "San Juan Nepomuceno" in the Battle of Trafalgar, when a cannon ball caused him injuries that cost him his life.
Split into simpler sentences: Cosme Damián de Churruca an officer of the Spanish Navy, performed heroically in a siege of Gibraltar. He also commanded the 74-gun "San Juan Nepomuceno" in the Battle of Trafalgar, when a cannon ball caused him injuries that cost him his life.