In the politics of the United Kingdom, the Cabinet is a formal body composed of the most senior government ministers chosen by the Prime Minister. Most members are heads of government departments with the title "Secretary of State". Formal members of the Cabinet are drawn exclusively from the House of Commons and the House of Lords.In traditional constitutional theory, in the British system of government, the Cabinet is the key formal decision making body of the executive. This interpretation was originally put across in the work of nineteenth century constitutionalists such as Walter Bagehot (who described the Cabinet as the 'efficient secret' of the British political system in his book 'The English Constitution'). The political and decision-making authority of the cabinet has been gradually reduced over the last several decades, with some claiming its role has been usurped by a 'Prime-Ministerial' (i.e. more 'presidential') government.Originally, the Cabinet merely served as a sub-committee to the Privy Council. However, the modern Cabinet system was set up by Prime Minister David Lloyd George during his premiership of 1916-22, with a Cabinet Office and Secretariat, committee structures, Minutes, and a clearer relationship with departmental Cabinet Ministers. This development grew out of the exigencies of the First World War, where faster and better co-ordinated decisions across Government were seen as crucial part of the war effort. Lloyd George himself once said, "War is too important to be left to the generals."Decisions on mass conscription, co-ordination world-wide with other governments across international theatres, armament production tied into a general war strategy that could be developed and overseen from an inner "War Cabinet", 10 Downing Street, are all clear elements retained today. As the country went through successive crises after the 1922-1926 General Strike, the Great Depression of 1929-32; the rise of communist Bolshevism after 1917 and Fascism after 1922; the Spanish Civil War 1936 onwards; the invasion of Abyssinia 1936; the League of Nations Crisis which followed; the re-armament and resurgence of Germany from 1933, plus the lead into another World War - all demanded a highly organized and centralized Government based around the Cabinet.This centralization inevitably enhanced the power of the Prime Minister, who moved from being the primus inter pares of the Asquith Cabinets of 1906 onwards, with a glittering set of huge individual talents leading powerful departments, to the dominating figures of Lloyd George, Stanley Baldwin and Winston Churchill.