The escape of Roger de Mortimer from the Tower of London where he had been imprisoned for leading a revolt against king Edward II in 1322. Roger de Mortimer, 3rd Baron Mortimer, 1st Earl of March, 1287 1330. English nobleman and powerful Marcher lord. A Marcher Lord was a strong and trusted noble appointed by the King of England to guard the border (known as the Welsh Marches) between England and Wales. From Cassell's History of England, published c.1901