Summary
Costello was the eldest surviving son of the pioneer, pastoralist and explorer John Costello, an early settler in some of Queensland's most inhospitable regions. He grew up on his father's remote stations, sometimes accompanying him on risky expeditions driving stock overland during drought conditions. He published one novel, Harold Effermere: A Story of the Queensland Bush (1897). His 1930 biography of his father, Life of John Costello, received recognition for the significance of its subject matter, but drew criticism for having 'no literary style'.