When his mother, the formidable Black Agnes, bequeathed him the troubled earldom of Moray in the far north of Scotland, John Cospatrick, younger son of the ninth Earl of Dunbar and March, found himself unexpectedly elevated to become King David's lieutenant and arbiter up in those unruly parts.

At the age of 22, with no experience in matters of governance, John's courage, sharp wit and skills of diplomacy served him well in bringing the rebellious Lords of the Isles to heel.

However, the greatest test of his abilities as an envoy and negotiator was to come when the new king, Robert II, sent him to London to seek to win over the English king's brother, John of Gaunt, to friendship with Scotland.

'Through his imaginative dialogue, he provides a voice for Scotland's heroes' Scotland on Sunday