Baron Merthyr, of Senghenydd in the County of Glamorgan, is a title in the Peerage of the United Kingdom. It was created in 1911 for the Welsh coal mining magnate Sir William Thomas Lewis. He had already been created a Baronet, of Senghenydd in the County of Glamorgan, in 1896. The barony is named after the town of Merthyr Tydfil, where Lewis was born. His great-grandson, the fourth Baron, disclaimed the peerage for life on April 26, 1977, three weeks after succeeding his father. He does not use his title of Baronet either. The Peerage of the United Kingdom comprises most peerages created in the United Kingdom of Great Britain and Ireland after the Act of Union in 1801. ... 1911 (MCMXI) was a common year starting on Sunday (click on link for calendar). ... 1896 (MDCCCXCVI) was a leap year starting on Wednesday (see link for calendar). ... Merthyr Tydfil (Welsh: Merthyr Tudful) is a town and county borough in the traditional county of Glamorgan, south Wales, with a population of about 55,000. ... The Peerage Act 1963 is a significant act in the history of the British Peerage. ... April 26 is the 116th day of the year in the Gregorian Calendar (117th in leap years). ... For the album by Ash, see 1977 (album). ...