They were the British ambassadors, ambassadors of the largest empire the world had ever seen. In the era stretching from the victorious conclusion of the Great War to the outbreak of the Second World War, there were fifty-one such paladins. Forty-five were career diplomats, five politicians, and one a senior India Office official. The First World War had led to most ambassadors in post being extended, often well beyond normal retirement. Once the war had ended a mass retirement ensued, with a comparative flood of promotions. Only two of the appointments had held such rank previously, Lord Hardinge and Sir George Buchanan. The First World War thus provided a watershed in the rise of a new generation of diplomats to the top posts. The ambassadorial cadre provides a view of the British Diplomatic service during this period, at a time when it was under increasing threat of politicization and patronage appointments. The survival of a professional service and the maintenance of high morale among its most senior officials was an ongoing struggle.