Prequel of the medieval Welsh Kingdoms (Gwynedd)

Roman occupation of Wales in brief (Wikipedia links used)

The Roman conquest of Britain began in 55 BC and ended in 410 AD. During this period, the Celtic British Kingdoms were established throughout Great Britain. The Celtic tribes resisted the Roman invasions from mainland Europe for over a century, however, the turning point was in 52 AD when the leaders of the tribes surrendered to the Roman Emperor, Claudius who had previously invaded less than a decade before. Britain (Britannia) was divided into 4 provinces ruled by Governors.

Arch of Claudius Latin inscription image from wiki source, Jenni Ahonen, Capitoline museum inscription.

 “For Tiberius Claudius Caesar Augustus Germanicus, son of Drusus, High Priest, holding tribunician power for the eleventh time, Consul for the fifth time, hailed Imperator in the field twenty-two times, Censor, Father of his country. The Senate and the People of Rome [have dedicated this] because he accepted the surrender of eleven British kings, subdued without any losses, the first to reduce barbarian tribes across the Ocean to the rule of the Roman people.” Latin language quote inscribed 2,000 years ago and now found in the Capitoline Museum, Rome, Italy.

During the Roman occupation of Wales, Anglesey was invaded twice. The first conquest was around 60/61 AD, the Druid Welsh Celtic Ordovices (they did not submit to Claudius) tribe were decimated by Gaius Suetonius Paulinus and his Roman forces at Castell Bryn Gwyn (named by locals 'Bryn Beddau', or the "hill of graves"), an Iron Age hillfort with stone hut roundhouses built centuries before on a site occupied for millennia near present-day Llanidan, Anglesey. The Welsh Ordovices tribe had attacked and almost destroyed the Roman cavalry stationed in North Wales in retaliation and were again invaded (77 AD). Next time by Gnaeus Julius Agricola, the Welsh tribe was defeated in battle by Romans in 78 AD (sherds of Roman pottery at Aberffraw, Anglesey royal court dated to 27 – 387 AD). The events in Angelsey and the rest of Britain were recorded by the then-contemporary Roman historian Tacitus, he was the first to name the island to the northwest of Wales (Cambria), he called it Mona, a name still in use today in the Welsh language, Ynys Môn (Isle of Anglesey). During the Roman period, Welsh tribe members from North Wales (United Kingdom) fled further north than the then-Roman province to relocate for their safety to another Celtic tribe in the Orkney Islands, Scotland.

Image from Wiki Commons, attributed to Notuncurious, Pre-Roman Wales.

At the time of the Roman invasion c. 0AD, Wales was split into 5 Celtic tribes, Decangli (north-east), Ordovices (mid to north-west), Silures (south-east), Demetae (south-west) and Gangani (north-west, Llŷn Peninsula). Of the tribes, Gangani settled the Llyn peninsula much later as observed from Iron Age Wales. The Llyn tribe were of Irish origins according to a Greco-Roman historian, Ptolemy. Llŷn peninsula was a core part of the then-future Kingdom of Gwynedd and was also aligned with the Isle of Anglesey and the Eryri (Snowdonia) mountain range in the north-west of Wales. Llyn was inhabited by the Celtic Ordovices (later Gangani) tribe for a thousand years, that was prior to the Roman invasion and their empire which surrounded the Mediterranean Sea between western Asia to the east, then western Europe and also north Africa.