Wiki information Riderch:

Riderch II of Alt Clut
Noble person, Deceased Person, Person

Riderch II was, according to the Harleian genealogies, the son of Eugein II, the son of King Dumnagual III of Alt Clut. He is known only from this source, and there is no direct evidence he was king of Alt Clut, although he is usually regarded as...

Dumnagual IV of Alt Clut
Noble person, Person

Dumnagual IV was a 9th-century British figure thought to have been a ruler of Alt Clut, the kingdom later known as Strathclyde. According to the Harleian genealogies, he was the son of his predecessor Riderch II, the grandson of Eugein II, and the...