Welsh (Monmouthshire): from the Old Welsh personal name Seisyllt, an altered form of the Latin name Sextilius, a derivative of Sextus meaning ‘sixth’. The spelling has been modified as a result of folk etymological association with the Latin name C(a)ecilius, a derivative of caecus ‘blind’.
FOREBEARS The great and powerful English Cecil family first came to prominence with David Cecil, a Monmouthshire gentleman who espoused the cause of Henry Tudor and came to court in London after the latter became king in 1485. His grandson William Cecil, Lord Burghley (1520–98), was Elizabeth I's chief adviser for 40 years, and his descendants have remained politically powerful and culturally influential in Britain ever since. They were originally minor Welsh gentry; their name is found in a variety of forms, including Sitsylt, Ceyssel, and Sisseld.
