William Edward Arnold-Forster (1886–1951) was an English author, artist, educator, gardener, Labour Party politician and retired naval officer.

He was married to Katherine Laird Cox, a former member of the Bloomsbury group, and associated with Rupert Brooke and the Neo-pagans at Cambridge University.

He moved to Italy in 1911, living near Fiesole in Tuscany until 1914[4] when he returned to England at the beginning of World War I, joining the Royal Navy and working in the Admiralty, having previously been a naval cadet.

After the war, he married Katharine ("Ka") Laird Cox, who was then working at the Admiralty and moved with her to Zennor on the Cornish coast, near St Ives, where they purchased 'The Eagle’s Nest'.

With the rise of the Nazi Party in Germany, Hahn, a Jew, was imprisoned, but was released with the assistance of the Arnold-Forsters and fled to Scotland in 1933.

The Arnold-Forsters with Hahn were then instrumental in the founding of Gordonstoun, of which Arnold-Foster was the first chairman of the board of directors,[8] where Mark continued his education as one of the first pupils, till 1937.