On 9 May 1423 he was appointed the King's lieutenant in Ireland for nine years, but at first exercised his authority through a deputy, and remained in England.
1423年5月9日，莫蒂默被任命为国王的爱尔兰助理，为期9年，但是他起初只通过一个副手代行职权，自己仍留在英格兰。