This Alexander, known as 'Little Breeches' because he followed the Continental fashion of short trousers, was responsible for the building of the Jacobean mansion of Drum Castle in 1619. He was Sheriff of Aberdeen and he and his wife, Marion Douglas, were noted local philanthropists.

The laird was rich enough to lend money to King James VI. He asked for a special dispensation to eat meat on Wednesdays and Fridays as well as other days, gave £10,000 for a scholarship at Aberdeen University - which survives today as the Drum Bursary - and a large number of other benefactions including '32 bolls of meal' for the poor people of nearby Drumoak. His wife also founded a hospital for spinsters in Aberdeen.