William was the son of Robert Thomas, was born in Fleet Street, London and emigrated to South Australia with his father in 1836, and from that time until the day of his death William was intimately associated with the fortunes of the South Australian Register, for the last twenty-five years of his life as one of the proprietors.
To his industry and ability in the different capacities in which he acted was due to a large extent the high character and phenomenal success of the Register, and the weekly and afternoon journals issued from the same office—the Adelaide Observer and Evening Journal. William died on 4 July 1878 in Glenelg, South Australia and was buried in West Terrace Cemetery. Rosetta Jane "Rose" Birks (1856-1911), the noted suffragist, was a daughter.
Captain Angus Clifford Mallam, Medical Corps, killed in action, 28 October 1918, was a grandson.
