Pat Shanahan won a scholarship to St Patrick's Christian Brothers College, Perth. He studied there for a time, but returned home to Bunbury during the Depression and took up work with the railways. Shanahan served with the army during World War II and worked in Japan with the occupying forces at the war's end.
After a further period of work in Western Australia, Shanahan re-located to Canberra. While there, he completed the examinations for the New South Wales bar and then became a barrister in Sydney.
During the post-war period, Shanahan wrote short stories for magazines such as Man and Man Junior (using several pen names including Nicholas Patrick), and wrote romantic pieces for the Australian Women's Weekly.
Source: Harriet Veitch, 'Soldier-Lawyer Also Wrote Romance Stories', Sydney Morning Herald (11 June 2009): 20.