Nobody, actually. Wales was a principality, the highest ranking nobleman being a prince. One of the agreements made to bind Wales wth England (way back when) was that the next king of England would be whomever was the reigning prince in Wales. Then the English family in power installed their next-in-line-to-the-throne as the prince, replacing the Welshman. Tricky. Anyway, that is why the heir to the English throne is always also the current "Prince of Wales".

I disagree - the term Prince of Wales only became used following England's conquering of Wales in the 13th century. Wales as we know it today was defined by the advancing Saxons in the 6th to 9th centuries and originally consisted of a series of small kingdoms (Gwynedd, Powys, Morgannwg, Gwent etc) each with their own king. Sometimes the kings united one or more individual kingdoms, but the first king to unite all of Wales was arguably Grufydd ap Llywelyn - initially King of Gwynedd and Powys from 1039 to 1057 and for all Wales from 1057 to 1063.

Answer 3

I also disagree. The English fought the Welsh to gain control of Wales.

Rhodri the Great (in Welsh, Rhodri Mawr; occasionally in English, Roderick the Great) (c. 820--878) was the first ruler of Wales to be called 'Great', and the first to rule most of present-day Wales. He is referred to as "King of the Britons" by the Annals of Ulster. In some later histories, he is referred to as "King of Wales" but he did not rule all of Wales nor was this term used contemporaneously to describe him. Rhodri faced pressure both from the English and increasingly from the Danes, who were recorded as ravaging Anglesey in 854. In 856 Rhodri won a notable victory over the Danes, killing their leader Gorm (sometimes given as Horm).

The son of Merfyn Frych, King of Gwynedd, and Nest ferch Cadell of the Royal line of Powys, he inherited the Kingdom of Gwynedd on his father's death in 844. When his maternal uncle Cyngen ap Cadell ruler of Powys died on a pilgrimage to Rome in 855 Rhodri inherited Powys. In 872 Gwgon, ruler of Seisyllwg in southern Wales, was accidentally drowned, and Rhodri added his Kingdom to his domains by virtue of his marriage to Angharad, Gwgon's sister. This made him the ruler of the larger part of Wales.