The clan claims descent from an Edinburgh lawyer who lived in the 16th century and from a distinguished line of Aberdeen merchants who preceded him.

The Lord Lyon King of Arms accepted this man's petition on the condition he took the surname MacNeacail.

This is because in late 17th century members of Clan MacNeacail began to Anglicise their Gaelic name to Nicolson.

[3] During the Scottish–Norwegian War, the last Norse king who invaded Scotland, Haakon IV of Norway, sent an advance party under Anders Nicolassen who was his foster brother and one of his chief barons, to plunder the Isle of Bute before joining the main Norse fleet off the coast of Largs.

[3] In the ensuing Battle of Largs, the Norsemen were defeated but there is a persistent tradition that Anders Nicolassen settled in Scotland after he had been sent as an envoy from Norway to conclude the Treaty of Perth.

[3] James's older brother, John, acquired the lands of Lasswade from Sinclair of Dryden in 1592.

The motto which appears on the crest badge is GENEROSITATE, which translates from Latin either as "by generosity" or "by inheritance", or a combination of the two.

[7] The heraldic elements with the crest badge are derived from the Arms of Nicolson of that Ilk.