Patrick Joseph Hartigan (13 October 1878 – 27 December 1952) was an Australian Roman Catholic priest, educator, author and poet, writing under the name John O'Brien.
He was born at Yass in New South Wales Patrick Joseph Hartigan and studied at St Patrick's Seminary, Manly and St Patrick's College, in Goulburn. His poetry was very popular in Australia and was well received in Ireland and the United States. He died in Lewisham, an inner suburb of Sydney in 1952.
His most popular poem would surely have been "Said Hanrahan" in which those immortal words appeared "We'll all be rooned", said Hanrahan.
(Some of the above information sourced from Wikipedia.)