He was the youngest son in a large family born to Anglo-Irish surgeon Robert Charles Alexander and Jane Elizabeth Lindsay (née Williams), of Creswick, Victoria, who had ten children.

Daryl and his brothers Percy (the eldest), Lionel, and Norman, achieved distinction in the arts.

[1] Following his active service in France, in England he made a very substantial contribution to the advancement of military reconstructive surgery with the extensive set of images he produced for Sir Harold Gillies, while serving as Lieutenant D./E.

Lindsay, the official "medical artist" at the specialist military hospital at Sidcup, in Kent.

When the couple returned to live in Australia, they built a house called Mulberry Hill at Langwarrin South, on the Mornington Peninsula, and lived there until the Great Depression forced them to take more humble lodgings in Bacchus Marsh, renting out their home until the economic situation improved.