Complex sentence: Henry VIII's consorts, Anne Boleyn and Catherine Howard were both executed for treason, as adultery, when committed by a queen consort of England, was legally an act of High Treason, punishable by death.
Split into simpler sentences: Henry VIII's wives, Anne Boleyn and Catherine Howard were both executed on the grounds of treason. Adultery, when committed by a queen consort of England, was legally an act of treason, punishable by death.