In his youth he served in the Williamite army, but later was received into the Catholic Church where he trained as a Franciscan.
He received priesthood education from English Franciscans in Douai College in France.
[1] He served as bishop of Killaloe (1728–1739) and subsequently of Waterford and Lismore (1739–1747).
He was active but not particularly successful in drumming up support for the Jacobite cause in both Catholic and Protestant circles.
Patrick Fagan: An Irish bishop of penal times: The chequered career of Sylvester Lloyd O.F.M., Dublin, Four courts Press,2004