May 15, 1536 - Anne Boleyn's trial for treason began. She was accused on trumped up charges of adultery and incest, sleeping with 4 men (including her brother George), and an assassination plot against her husband, Henry VIII. She was found guilty and executed four days later.Her brother George's trial took place immediately after her's and he was found guilty as well.
May 15, 1567 - Mary Queen of Scots married the Earl of Bothwell at Holyrood Palace. Her husband, Lord Darnley, had been assassinated only three months earlier and many thought she and Bothwell were involved.