After a period as an engineering draughtsman in the Royal Flying Corps during World War I, Hardiman was elected a member of the Royal Society of British Sculptors in 1918. 

He resumed his studies and in 1920 was awarded the Prix de Rome, spending two years at the British School at Rome. 

Hardiman’s best-known public commission is the controversial Earl Haig Memorial situated in Whitehall, London. It caused outrage in some circles as Hardiman did not depict Haigh’s likeness as his widow Lady Haigh had expected. It was not completed until 1937.

More widely admired are his heraldic lions flanking the main entrance to the City Hall, Norwich, a work which more fully represents his style. Hardiman also carved three large stone figures for the council chamber. 

Other public commissions include statues at County Hall, Westminster, a memorial fountain at St James's church, Piccadilly, in remembrance of Viscount Southwood and a statue of Cecil Rhodes in Oxford. 

Hardiman who was a member of the Chelsea Arts Club was elected an Associate of the Royal Academy in 1936 and a full member in 1944. He was awarded a Fellowship of the Royal British Society of Sculptors in 1938. 

Bibliography: Sculpture and the Pursuit of a Modern Ideal in Britain, c. 1880-1930 edited by David J. Getsy. Published by Ashgate Publishing Limited, 2004. ISBN: 0754609960. A kick in the teeth : The equestrian monument to Field Marshal Earl Haig, Commander-in-Chief of the British Armies in France 1915-1918 by Alfred Hardiman by Nicholas Watkins. Published by Henry Moore Institute, Leeds, 2008. ISBN 9781905462179 .