William was the eldest son of Richard Nancarrow born in Cornwall. His mother was Philippa Allen born in Cornwall about 1820 and died in Hotham West in 1897.
William was their only son, born about 1852 in Truro, Cornwall about 1852. He had a sister, Elizabeth also born in Cornwall, married to Richard Seymour of Hythe, Kent in 1857.
William married Phoebe Frances Payne on 7th July 1877. Phoebe died in 1927.
They had two children:
Phoebe born 9 July 1880 in Cruikshank Street Port. Phoebe married Joseph Tyrrell who was born in Boundary Street, Port Melbourne 1885, he died in Seymour in 1940.
Richard born 1882 in Sandridge. Richard married Estelle Mary Thorne; They had seven children, only the first of whom, Richard James, was born in Port Melbourne in 1908.