According to W.C. Cheyne-Macpherson's Chiefs of the Clan Macpherson, Euan was born in 1782, the eldest son of Lachlan Macpherson of Ralia. He became a Major in the 42nd Madras Infantry, and married Miss Helen Birrell, niece of Sir James Ramsey of Balmain. On his return from India he purchased Glentruim and became the 1st of Glentruim.
His younger brother, Lt James Macpherson distinguished himself at the Siege of Badajoz in Spain (1814). His exploit is described at Panel 43. The Macphersons of Ralia are one of the cadet families of the Cluny line.