Amateur rider Patrick Gill Dyke Dennis was born on July 7, 1899. He rode his first winner on Hazel Dawn in the Bryn-y-Pys Chase at Bangor-on-Dee on 1 April 1921.
He went on to ride a total of 44 winners over jumps in Britain. He achieved his greatest success when winning the 1925 National Hunt Chase on the 12-year-old Ardvasar. The winner had finished seventh in the race in 1922 when making his racecourse debut.
Pat rode in three Grand Nationals but fell each time, on General Saxham in 1922, Rousham in 1925, and Jolly Glad in 1926.