He defeated those enemies in a civil war that made him even more powerful. He had a famous love relationship with Cleopatra, the queen of Egypt. When it seemed that nothing could hold him back, he was assassinated in the Roman Senate. One of his most notable accomplishments still affects people today. He reformed the calendar and established the length of a year at its present 365 days, with a leap year every four years. The month of July is named after him.