While the exact origin of the Leask name is unknown, the first mention of the clan in Scottish records occurred in 1296 when William de Laskereske appeared on the Ragman Rolls – a document in which the Scottish nobility and gentry subscribed allegiance to King Edward I of England as his army advanced north into the country in order to keep their lands.
Later William Leask would receive a charter granting him lands at Leskgoroune or Leskgaranne from David II of Scotland, son of Robert the Bruce in 1345.
The clan would then suffer disaster when the family invested a large amount of their money in the failed Darien Venture – a disastrous attempt by Scotland to start an overseas colony at Panama which almost bankrupted the country due to its failure.
Following this disaster, Alexander Leask of that Ilk, the thirteenth chief was forced to give up his estates which were taken over by Robert Cumming and it is not until 1963 that the history of the clan resumes.
It was in this year that a descendant managed to buy back a portion of the family lands and established the Leask Society, with the support of other prominent Leasks. Since then the clan has had a thriving society and the current clan chief today is Jonathan Leask, the 23rd chief of Clan Leask.