The London venture

An Armenian, born Dikran Kouyoumdjian in Bulgaria, Arlen became a popular writer in England in the '20s (Wikipedia, Tartarus). After coming to England to complete his education, Kouyoumdjian adopted the name Michael Arien following his decision to become a British citizen and pursue a literary career. Although Arlen published his first book at the early age of eighteen, it was not until eleven years later that he achieved real success with The Green Hat (1924). A fashionable series of best-selling society novels and short stories followed, perfectly capturing the hedonistic spirit of the times. Arlen eventually married into the English upper-class society he so often satirised and moved first to France and later to Hollywood to develop his career. Among his fictional works, Arlen wrote a number of supernatural pieces which demonstrate a variety of literary infuences ranging from Saki and Oscar Wilde to Arthur Machen. [Source: Shadows in the Attic: A Guide to British Supernatural Fiction 1820-1950, Neil Wilson (2000).] Michael J Arlen, who also appears in Open Library (here) is probably the son mentioned in the Wikipedia link.