Maredudd was Owain Glyndwr's only surviving legitimate son and as such succeeded him in the August of 1419 to the title of Prince of Wales. Under the terms of the Treaty of London, which had ended the 1st War of Independence, Maredudd was the vassal Prince of Wales, under the King of England (at this time Henry V). By the end of his reign he had united all Welsh territory under his rule, had thrown off his vassal status (though the Welsh Crown would continue to pay lip service at the very least until the reign of Richard III) and the achievement which would raise his reign above his fathers, he was crowned and acknowledged as King of Wales.