Sykes is also remembered to a lesser extent, for his history of the British Mandate of Palestine, "Crossroads to Israel" (1965). He also wrote several books of fiction and lives of Orde Wingate (published 1959 - Sykes drew attention to Wingate as the possible basis for Waugh's character Brigadier Ritchie Hook in "The Sword of Honour" trilogy, in his biography of Waugh) the general sometimes known as the "Lawrence of Judea" (a phrase that Wingate deplored); Lady Astor, who, born in Virginia, was one of the first women to sit in the House of Commons of the United Kingdom; and Adam von Trott zu Solz, executed following his part in the failed 20 July plot to assassinate Hitler.