Born at Stocking Pelham Rectory, near Bishops Stortford, Hertfordshire Alfred was one of four sons of Revd Charles Hartley, rector of Stocking Pelham and his wife Hannah nee Welsh, who had married at Camberwell in 1848. His studies were taken at Royal College of Art, South Kensington, and at Westminster School of Art under Brown. Moving back to Camberwell with his family and then to Dunmow, Essex, he was a member and exhibitor at the Ipswich Art Club from 1891-1903 and described as a member of the Royal Society of Painter-Etchers and Engravers.
He married at Hastings, Sussex on 5 May 1896, Leonora Locking (1856-1943), also an artist and in 1901 the couple were staying with wealthy 41-year-old Annie Gurney at 18 Palace Garden Terrace, Kensington.
Hartley moved to St Ives with his wife, aka Nora, in 1904, living consecutively at two addresses on Bellair Terrace (No 7 being one of these). They joined the St Ives Arts Club in 1906. During his time in St Ives, Hartley was known as a master in etching and coloured aquatint, and went on to develop an international reputation for print work.
In 1907 he exhibited and sold the etching An Essex Stream at NAG. He also founded the New Print Society in St Ives, and in 1911, 1913 and 1924 exhibited at St Ives Show Days. In 1924, both he and his wife showed work from their travels to Bordighera, Italy, Alfred showing charming small pastel studies, Nora painting the streets and the town. He was a master at evocative atmospheric effects, though in his later years he became crippled with arthritis. He died in the East Preston district of Sussex in 1933, aged 78.