The events leading up to the next invasion are unclear, but in November 1093, Malcolm leads an army into Northumbria and begins to besiege Alnwick.

Malcolm is accompanied by Edward, his eldest son by Margaret and probable heir-designate (or tánaiste), and by Edgar.

Even by the standards of the time, the ravaging of Northumbria by the Scots is seen as harsh.

At this time, Robert de Mowbray is Earl of Northumbria, having been pardoned following his part in the Rebellion of 1088, against William II.

He is also governor of Bamburgh Castle, a stronghold on the Northumbrian coast.

Mowbray does not have a sufficient force at his command to oppose the Scottish army in open battle.

However, he sets out to try to relieve Alnwick.

He arrives here with his forces on November 13 (known as St. Brice’s Day) and catching the Scottish army by surprise, the English knights attack them before the ramparts of Alnwick.

While marching north again, Malcolm is ambushed near Alnwick on November 13, 1093, by Robert de Mowbray, whose lands he has devastated.

Here he is killed by Arkil Morel, steward of Bamburgh Castle.

The conflict becomes known as the Battle of Alnwick.

Edward is mortally wounded in the same fight.

With Malcolm’s death, the Scottish army finds itself leaderless, and heads back to Scotland.

Malcolm's body is taken to Tynemouth Priory for burial.

The king's body is sent north for reburial, in the reign of his son Alexander, at Dunfermline Abbey, or possibly Iona.