Glywysing, Glevesing, Gwlad Gliwys

An early medieval Welsh kingdom located in the southern part of present-day Wales, roughly corresponding to the modern counties of Glamorgan and Monmouthshire. It existed during a period of political and territorial changes in Wales and played a role in the evolving landscape of Welsh kingdoms.

The village of Elledi was located in the territory, which was the home of the child Ambrosius.

Glywysing is associated with the early medieval period in Wales, roughly from the fifth to the seventh centuries. The founder of the kingdom was King Glywys (Gwlyw), who gave his name to the realm. King Glywys is mentioned in various medieval Welsh genealogies and texts, and he is traditionally considered a descendant of Brychan Brycheiniog, a legendary figure associated with several early Welsh dynasties. King Glywys was a Christian ruler, and the kingdom became a center of early Christian activity.

By the eighth century, Glywysing had diminished in significance, and the area experienced changes in political and territorial control. Glywysing was eventually absorbed into the larger kingdom of Morgannwg, which included parts of Glywysing and other territories.

Glywysing is best known as the homeland of Saint Cadoc, a prominent Welsh saint and scholar who lived in the sixth century. Cadoc was a disciple of Saint Tathyw, and he is credited with founding several churches and monastic communities in the region. The Llancarfan Church in Glamorgan, associated with Saint Cadoc, became an important center of learning and religious activity during this time.