Father Hayes was born in 1889 at Frederickton, New South Wales, and began book collecting at age seven. He commenced studies for the priesthood at St Columbia's College, Springwood, in 1911 and was ordained after further study at St Patrick's, Manly, in 1918. Over the course of 70 years he amassed one of the greatest collections of Australiana, including more than 25,000 volumes, 30,000 manuscript items, 1,500 Indigenous artefacts, maps, stamps, coins, weapons, geological specimens, cattle bells, and a variety of other material. On 19 - 20 October 1967 a convoy of removal trucks transported eighty large crates and 400 cartons of material to The University of Queensland Library at St Lucia, doubling its holdings on Australian subjects and effectively putting the Library on the map as an institution capable of supporting high-level research in Australian studies -- excerpted from Found in Fryer.

O'Brien was an explorer and historian. From 1941-1965 he was the Honorary Director and General Secretary of the Royal Geographical Society of Queensland.