Born in Aberdeen on 12 March 1879, AGR was the second son[1][2] of Marshall Mackenzie, architect and his wife, Phoebe Ann Robertson Cooper.
From 1900, to gain London experience, he worked in the office of Colonel Edis (1839–1927), and studied at the Architectural Association and the Central School of Arts and Crafts.
[1] The London practice was an immediate success, with commissions for the Waldorf Astoria Hotel in Aldwych and a more prestigious one for Canada House (which was cancelled during World War I).
[3] In Aberdeen he designed the Art Deco style Northern Hotel which was built in 1937–8,[4] retrieved Provost Ross' House from ruin (now part of the Maritime Museum).
[1] He died on 20 March 1963, after major surgery and is buried at Bourtie churchyard, AGR was admitted ARIBA in 1901 and elevated to FRIBA in 1913.