The French ‘mercier’, or ‘merchant’, is generally understood to be the most likely origin of this name. The name Le Mercer (‘the merchant’) is fairly common in medieval records throughout England, Scotland and Ireland. The name is, of course, still used to describe the trade of a silk dealer. In Scotland, William Le Mercer witnessed two charters in favour of Kelso Abbey, around 1200. Aleumnus, or Alcunus, Mercer had a grant of lands at Tillicoultry in Stirlingshire from Walter Fitzalan. These lands were resigned to the king in 1261. A Walter Le Mercer of Montrose and Augustine Le Mercer of Roxburgh were both recorded in 1296, suggesting several origin points for parts of this family.

The principal and most prominent family were the Mercers of Aldie, who held land around the ancient Abbey of Scone and had the lands of Aldie confirmed to them by a charter of 1362. John Mercer was a counsellor to the king between 1364 and 1367, and was ambassador to England and France. Sir Andrew Mercer received further lands from Robert II in 1378 and 1381. Sir Lawrence Mercer sat as a minor baron in the Parliament of 1481. There were numerous cadet houses, including the Mercers of Inchbrakie, of Newton and Forgandenny, and of Kimrain. The principal family were latterly styled ‘of Huntingtower’. William Mercer of Huntingtower, sometime major in the Sixteenth Lancers, entered politics in Australia and promoted the erection of Victoria as a state separate from New South Wales.

There are two rhymes relating to this family and their extensive holdings around Perth. One has it ‘sae sycker ’tis as onie thing on earth, the Mercers aye are aulder than auld Perth’. The other relates to the endowment of St John’s Church in Perth, with the two inshes, or islands, beside the river in return for the perpetual right of burial in the churchyard. This was a generous gift but led to the inevitable witticism, ‘Folk say the Mercers tried the Town to cheat when for just two inches they did win six feet’. Brigadier General Hugh Mercer, who fought under George Washington in the American War of Independence, was said to have been a surgeon at the Battle of Culloden. He fought at the Battles of Trenton and Princeton in America in the winter of 1776-77, and died of wounds sustained during that campaign. The Mercers are still prominent in Perthshire.