Owen Mac Dumnagual
Reigned from 760 to abt. 780. Nothing is known of the reign of the four kings, Owen mac Dumnagual, Rhydderch II, Cynan mac Rhydderch, and Dumnagual IV, other than their names in the genealogies, according to Mike Ashley's "Mammoth Book of British Kings & Queens." Ashley believes they were "almost certainly subordinate to Northumbria and it is not certain whether they had any authority as kings or even vassals."
Reigned in Strathclyde from 752-760. "The son and successor of Teudebur, after whose death Dumnagual entered into an alliance with Eadbert of Northumbria, which resulted in Strathclyde losing the territory around Kyle to the south," according to Mike Ashley's "Mammoth Book of British Kings & Queens."
Teudebur Mac Bili
Reigned in Strathclyde from 722 to 752. Teudebur's reign was under the domination of the Northumbrians, Picts, and Scots, consecutively. During his administration, the Picts gained power under their King Angus, who dominated northern Britain from 730 to 750. In 750, however, Teudebur overcame the Picts at the Battle of Mygedawg (believed to be Mugdock, a few miles east of Dumbarton). This halted Pictish control of Strathclyde. Unfortunately, since it was the Picts who had kept the Northumbrians out of Strathclyde for many years, this now left the door open to an invasion from Northumbria by Eadbert, who then conquered and annexed the territory of Kyle. Teudebur died that year, probably killed in battle.
Bili II Mac Elphin
Bili's reigned was focused on maintaining Strathclyde as it increasingly became a battle ground for the Picts, Scots, and Northumbrians. "Bili was one of the provincial kings who witnessed the Law of Innocents promulgated by Adomnan, the Bishop of Iona, at the Synod of Birr in Ireland in 697," according to Mike Ashley's "Mammoth Book of British Kings & Queens." This law "endeavored to protect the clergy, women, children and the elderly from the constant warfare of the seventh century." According to Ashley, "Bili was drawn into battle against the at least twice against the Scots and on both occasions defeated, but he still retained his kingdom."
Dumnagual or Domhnall II
Reigned in Strathclyde from 658 to 694. Possibly not the only ruler of Strathclyde at this time.
Reigned in Strathclyde from 645 to 658. Nothing is known of his reign, other than his death in 658.
Owen Mac Bili
Reigned in Strathclyde from 633 to abt. 645. Inherited the kingdom of Strathclyde at a time when it was threatened by invasions from all sides. Was probably very young when he became king, but seemed able enough to withstand any opposition and subsequently rebuilt the strength of Strathclyde. His expansion eastward, however, was prevented by Oswald of Northumbria. Owen's major acheivement was the defeat of Domnall Brecc, the king of the Dal Riatan Scots, at the Battle of Strathcarron in Stirlingshire in 642. This victory ended the domination of the Scots and briefly re-established Strathclyde as the leading force north of Hadrian's Wall. Owen's death is not recorded, but it is assumed he probably died of natural causes, as there is no record of his death in battle or by murder, which would have been recorded in song.
Bili Mac Nechtan
Reigned in Strathclyde from 621 to 633. Became king of Strathclyde soon after the accession of Edwin of Northumbria. Bili may have died at the Battle of Hatfiled Chase in 633, though it is not recorded that he took part in that battle, which was fought between Edwin of Northumbria and the Welsh, under Cadwallon. It is fairly certain that Bili died young, though.
Became King of the Picts.
Reigned in Strathclyde from 612 to 621.