Roman: Demetae, Demetia, Dumnonia
Dyfed was settled by Irish tribes during the traditional Arthurian period (fifth and sixth centuries). Geoffrey says it was ruled by Stater, the son of King Arthgallo, who was contemporary with King Arthur.
Dyfed | History
Early Periods and Post-Roman Period
Dyfed, or Demetia as it was called, has evidence of human habitation dating back to prehistoric times. During the Roman era, it was part of the larger territory known as Roman Wales. In the early fifth century, the Roman legions withdrew from Britain to defend the Roman Empire’s heartlands. This marked the end of Roman rule in Britain, leading to a power vacuum and the fragmentation of the territory into smaller kingdoms and tribal regions.
The kingdom of Dyfed emerged as one of the successor states in the southwestern part of Wales. The exact date of its establishment is uncertain, likely around the fifth or sixth century. It’s early history is somewhat obscure, as historical records from this era is limited.
Christianization and Welsh Culture
Demetia played a crucial role in the preservation of Welsh language, culture, and tradition during a period of significant political changes and external influences. Like other Welsh kingdoms, Demetia embraced Christianity during the early medieval period, and the spread of Christianity had a profound impact on the social and cultural life of the kingdom. Numerous Celtic Christian saints, such as Saint David and Saint Teilo, are associated with the region. Saint David, in particular, is considered the patron saint of Wales and is said to have founded a monastery at St. Davids, which became an important religious center.
The sixth century is considered a significant period for early Welsh literature. Poems and tales of heroic figures, such as Y Gododdin and Historia Brittonum, were composed, preserving aspects of early Welsh culture and history.
Kingdom of Demetia
Demetia was a distinct Welsh kingdom during the early medieval period. It occupied areas that later became part of the historic county of Dyfed, including parts of present-day Pembrokeshire, Carmarthenshire, and Ceredigion. In the seventh century Dyfed consisted only of Pembrokeshire.
Norman Invasions and Struggles
The Norman invasions of Wales in the eleventh and twelfth centuries had a significant impact on Demetia. Norman lords sought to expand their territories into Welsh lands, leading to conflicts and changes in political control. The region experienced internal struggles and external pressures during the medieval period. Norman influence, battles between Welsh rulers, and attempts to assert Welsh independence all contributed to the dynamic and often tumultuous history of Demetia.
The area was eventually annexed into the Kingdom of Deheubarth, a larger medieval Welsh kingdom that covered much of southwest Wales.
Formation of Dyfed
Over time, the name “Dyfed” became more commonly associated with the region, and by the twelfth century, it was widely used to refer to the area that was once Demetia.
The name “Dyfed” is believed to be derived from the Old Welsh word duv or dub, meaning “dark” or “black.” Another interpretation is this: Dyfed is located in the lowest part of the principality, which indicates the root of the word dyfed might be dwfn, which means “deep” or “low.”
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138