His grandfather, William Philip Molyneux, 2nd Earl of Sefton, founded the Waterloo Cup and the Grand National.
During the First World War, he served as an officer in the Royal Horse Guards in France and Belgium.
After pursuing a military career, he was appointed aide-de-camp to the Governor-General of Canada (1919), to the Viceroy of India, Lord-in-waiting to the King (1936–37) and Lord Mayor of Liverpool (1944–45).
His 16-year-old brother Cecil, had died aboard HMS Lion at the Battle of Jutland in 1916 and his 14-year-old sister a year later.
On his widow's death in 1980, Abbeystead and the Wyresdale Forest estate were sold to the Duke of Westminster.