Donnchada mac Crinain (Modern Gaelic: Donnchadh mac Crionain; 14 June 1001 — 14 August 1040) often known as Duncan I and nicknamed the Fighter (Scottish Gaelic: an Trodaiche) was the King of Scotland from 1035 until he was killed at the Battle of Pitgaveny in 1040. He was the son of Crínán of Dunkeld and Bethóc Ingen mac Maíl Coluim, the daughter of King Malcolm II.
|King of Scots|
|Reign||25 November 1035 — 14 August 1040|
|Coronation||3 December 1035|
|Born||14 June 1001|
Atholl, Perth and Kinross, Scotland
|Died||14 August 1040 (aged 39)|
Pitgaveny, Moray, Scotland
|Burial||22 August 1040|
|Father||Crínán of Dunkeld|
|Mother||Bethóc Ingen mac Maíl Coluim|
He succeded his grandfather in 1035 and ruled the kingdom effectively until in 1040 where he was killed by the forces of Macbeth, who became king. Duncan left behind three children. His oldest child, Malcolm, would kill Macbeth seventeen years later and became king as Malcolm III. His second son, Donald, would also became king as Donald III.