John Walwyn was the eldest son of Edmund Walwyn of Thornborough, Buckinghamshire and his wife Anne née Green, daughter of Thomas Green of Greens-Norton, Northamptonshire.
During the Hodgkinson River gold rush of the 1870s-1890'S the local Djungan population was decimated and the survivors were drawn to the fringes of mining settlements formed at Thornborough and Mount Mulligan.
A. L. Rowse, Bishop Thornborough: A Clerical Careerist, in Richard Ollard and Pamela Tudor-Craig (editors), For Veronica Wedgwood These Studies in Seventeenth-Century History (1986)