Tysilio

Saint Tysilio (also known as/confused with Saint Suliac; Tysilius, Suliacus; died 640 AD) was a Welsh bishop, prince and scholar.

Life
Tyslio was the son of the reigning King of Powys, Brochwel Ysgithrog, maternal nephew of the great Abbot Dunod of Bangor Iscoed and an ecclesiastic who took a prominent part in the affairs of Wales during the distressful period at the opening of the 7th century.

Tysilio probably started his career in Trallwng Llywelyn (Welshpool) and afterwards took up residence in Meifod where he was associated with Gwyddvarch and St Beuno.

He founded the second church in Meifod—the Eglwys Tysilio. His feast day, or gwyl-mabsant, was 8 November which was also the date of the patronal festival and "wakes" in the nearby parish of Guilsfield, where a holy well was dedicated to him—the Fons Tysilio.

Tysilio is traditionally said to be the original author of the Brut Tysilio, a variant of the Welsh chronicle Brut y Brenhinedd, although Brynley F. Roberts has demonstrated that the Brut Tysilio originated around 1500 as an "amalgam" of earlier versions of the Brut y Brenhinedd, which itself derives from Geoffrey of Monmouth's 12th-century Latin Historia Regum Britanniae.

Identity
St. Tysilio has been confused, historically, with Saint Sulien, with some scholars suggesting that they were the same historical character. The facts that they lived in different Celtic states, and had different feast days from antiquity, make this suggestion unlikely.

Place names
Today Tysilio's name is remembered in several church and place names in Wales, including Llandysilio in Powys, Llandissilio in Pembrokeshire, Llandysiliogogo in Ceredigion and Llantysilio in Denbighshire.

Most famously, it appears in the longest place name in the United Kingdom, Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch, part of which (shown bold here) means the Church of St. Tysilio. That name, however, is a late 19th-century invention for the burgeoning tourist industry in the area.