Born in England to an artistic family, Arthur Diehl by age 19 had abandoned his education at Oxford University to explore the Continent, for a period studying painting in Milan, Italy. He returned to England, establishing a studio in London. In 1889 Diehl exhibited a painting titled The Quay, at Aldeburgh at the Royal Academy. In 1891 Diehl travelled to the United States. Among his many jobs in the arts as a singer, actor and musician, Diehl also decorated piecework, such as snuffbox tops, to make ends meet. By the turn of the century, he had established studios in Englewood cliffs, then Lakewood and Asbury Park, New Jersey.
By 1912 and possibly through an introduction from friends in the theater, Diehl and his third wife spent their summers on Cape Cod in Truro and Provincetown where Diehl established studios. He was known to paint rapidly on small canvases usually composing his scenes from memory and entertaining onlookers as he painted, who in turn would often buy the works he completed right before them. Catering to tourists drawn to the Cape each summer as well as visitors to his studios, Diehl was indifferent to artistic reputation and happy to sustain his family through his painting. During the winter months, he would also reside in Saint Augustine, Florida, repeating the formula of his northern success, while still maintaining studios in Massachusetts and Hartford and New Haven, Connecticut.