The Irish War, sometimes referred to as the Anglo-Irish War, was a major military conflict from September 1935 until February 1937, fought beween Ireland and England over control of the Isle of Man and which later became a much broader international conflict, drawing the involvement of a division of the French Foreign Legion and the attention of various foreign nations. The war was the first armed conflict between England and Ireland since the 1815 Treaty of London separated the two, and was viewed by many on both sides as an attempt to re-establish the old British Empire. The French landing in Cork in October of 1936 and the subsequent landing in Cornwall a month later prompted the English to sue for an immediate ceasefire.
The war had multiple effects, ironically the largest one of them being in France. In Ireland, the war reaffirmed the might of the Irish state and cemented President Michael Collins as a national hero, and helped continue Ireland's rise to European relevance throughout the next several decades. In England, it resulted in the ouster of Premier Francis Cumberland and the insertion of the weak Neville Chamberlain in his stead, and is widely viewed as one of the causes for the depression of the 1940's and the Anarchy in the 1950's. In France, the efforts of Sebastien Bonaparte to forge a peace treaty between Ireland and England earned him the suspicion of his family and peers and led to his flight to Russia, which in turn began the French Civil War.