Son of Sir Edward Maunde-Thompson, paleographer and Director and Principal Librarian at the British Museum in 1901, Edward Mackenzie Maunde-Thompson assumed the sole surname of Mackenzie in 1900, affirming his descent from his great-great-great-great-grandfather, Sir Edward Mackenzie, the first Baronet (Nova Scotia), through his mother, Georgina Mackenzie. He also assumed the baronetcy.
Mackenzie lived in Melbourne for many years, was Lieutenant in the Australian Army Reserve, and was Aide-de-Campe extra to the Governor-General of Australia (the Earl of Hopetoun) in 1901.
As well as his verse he wrote on genealogy and heraldry, printing his work on his own private printing press, the Poseidon Press.