Llywelyn ab Iorwerth

Llywelyn ab Iorwerth, known as Llywelyn Fawr or 'Llywelyn the Great', was born in 1173 and became the Prince of Gwynedd in 1199. His reign marked a significant transformation for Gwynedd, which had been plagued by civil war for three decades. Under his leadership, the territory evolved into a powerful polity capable of exerting suzerainty over many other native Welsh rulers.

During his early years, Llywelyn faced the challenge of two uncles who divided the kingdom following the death of his grandfather, Owain Gwynedd. Determined to reclaim power, he engaged in battles against his uncles, ultimately capturing Dafydd ab Owain in 1197 and exiling him. By 1199, after a decisive victory in Arfon, he secured the throne of Gwynedd and established a treaty with King John in 1200, fostering a decade of relatively stable relations.

However, tensions escalated in 1210, leading to an invasion by King John in 1211. Llywelyn was compelled to negotiate and relinquish lands east of the River Conwy, but he regained them the following year through alliances with other Welsh princes. His influence grew, and he played a pivotal role in the baronial revolt that forced John to sign the Magna Carta in 1215, solidifying his position as a dominant power in Wales.

After King John's death, Llywelyn negotiated the Treaty of Worcester with Henry III in 1218. His later years were marked by conflicts with Marcher lords and the king, yet he also formed strategic alliances. The Peace of Middle in 1234 signaled the end of his military endeavors, as he maintained a truce that lasted until his death on April 11, 1240. He left behind a legacy of strength and unity in Wales, passing the principality to his son, Dafydd ap Llywelyn.