Óengus I of the Picts

Óengus mac Fergusa
King of the Picts
The figure of the Old Testament King David shown killing a lion on the St Andrews Sarcophagus is thought to represent King Óengus. The figure is dressed as a Roman emperor of Late Antiquity and wears a fibula like that of the Emperor Justinian on the mosaic at San Vitale, Ravenna.
Reign	732–761
Predecessor	Nechtan son of Der-Ile
Successor	Bridei mac Fergus
Died	c. 761
Burial	St Andrews
Issue	Bridei Talorgan
House	Óengus

Óengus son of Fergus (Pictish: *Onuist map Urguist;Old Irish: Óengus mac Fergusso, "Angus mac Fergus"), was king of the Picts from 732 until his death in 761. His reign can be reconstructed in some detail from a variety of sources.

Óengus became the chief king in Pictland following a period of civil war in the late 720s. During his reign, the neighbouring kingdom of Dál Riata was subjugated and the kingdom of Strathclyde was attacked with less success. The most powerful ruler in Scotland for over two decades, he was involved in wars in Ireland and England. Kings from Óengus's family dominated Pictland until 839 when a disastrous defeat at the hands of Vikings began a new period of instability, which ended with the coming to power of Cináed mac Ailpín.

Surviving Pictish sources for the period are few, limited to king lists, the original of which was prepared in the early 720s, and a number of accounts relating to the foundation of St Andrews, then called Cennrígmonaid. Beyond Pictland, the principal sources are the Irish annals, of which the Annals of Ulster and the Annals of Tigernach are the most reliable. These include materials from an annal kept at the monastery of Iona in Scotland. Óengus and the Picts appear occasionally in Welsh sources, such as the Annales Cambriae, and more frequently in Northumbrian sources, of which the Continuation of Bede's chronicle and the Historia Regum Anglorum attributed to Symeon of Durham are the most important.