Hugh Mackay was the eldest son from the second marriage of his father, George Mackay, 3rd Lord Reay to Janet, daughter of John Sinclair of Ulbster, Caithness.
[1] During the Jacobite rising of 1745 Hugh Mackay supported the British-Hanoverian Government and was Captain of the 2nd Mackay Independent Highland Company that fought at the Skirmish of Tongue on 25 March 1746,[2] where money and supplies were captured from a French ship,[3] and 156 Jacobites were taken prisoner.
[4] He also led his Independent Company at the Battle of Littleferry on 15 April 1746 where the Jacobites were again completely defeated.
[1] Hugh Mackay married in 1728 to Elizabeth, eldest daughter and co-heiress of George Mackay of Bighouse (and this is from where Hugh took his designation) and had sasine of the Bighouse Estate in Strathhallade on 28 February 1742.
[1] Hugh Mackay of Bighouse married secondly Isabella, daughter of Alexander Mackenzie of Lentran but this marriage produced no children.