What were the names of the four principal kingdoms in Scotland during the time of St Ninian's Mission?

The four principal kingdoms in Scotland during St Ninian's Mission were Pictland, Dalriada, Strathclyde, and Bernicia.

During the time of St Ninian's Mission, around A.D. 400, Scotland was divided into four principal kingdoms. Pictland was the largest, covering the area from the river Forth to the Pentland Firth. Dalriada was settled by the Scots from Ireland, located in what is now Argyllshire and the neighboring isles. Strathclyde was inhabited by the Britons, primarily in the valley of the Clyde. Bernicia was established by the Angles, extending from the river Tees to the Firth of Forth.