Edward de Courcy Clarke was born on 10 November 1880 at Waimate North. He completed a Master of Arts with first-class honours and was appointed a master at Auckland Grammar School. In about 1913 he left New Zealand to take up a position in the Geological Survey of Western Australia, eventually becoming Professor of Geology at the University of Western Australia for thirty years. The E. de C. Clarke Geological Museum in Perth bears his name.
His first wife, Sylvia Rose Dunlop (born Gisborne, 28 May 1886), died during her first pregnancy in 1912, after only eighteen months of marriage.
He met his second wife Josephine May Palmer in 1914 in the remote gold-mining town of Meekatharra; they married in 1917. Their three sons were
- Stuart (1918),
- Miles (1920), and
- John (1925).
Despite the trauma associated with New Zealand — the early death of his first wife, and a painful estrangement from the country of his childhood — he returned to New Zealand in 1950 after the death of Josephine. He lived with his sisters Mary and Frances, and their husbands the Scott brothers, near Pirongia for four years.
In his final year he lived with his sons in Victoria and Kalgoorlie, where he died in November 1956.
His son Miles de Courcy Clarke (1920–2001) became a doctor in Kalgoorlie and Perth, renowned for his care and humour. He went 183 metres underground a mine shaft to rescue trapped gold miners in 1953. He received the Order of Australia Medal in 1999.
His son John (born 1925) became a Rhodes Scholar, completed his PhD in Zoology at Oxford, and spent his career as an academic in London.