George I (George Ludwig von Guelph-d'Este) (28 May 1660 – 11 June 1727) was Duke of Brunswick-Lüneburg (Hanover) from 23 January 1698, and King of Great Britain and King of Ireland from 1 August 1714, until his death. He was also the Archbannerbearer (afterwards Archtreasurer) and a Prince Elector of the Holy Roman Empire. George I, the first Hanoverian monarch of Great Britain and Ireland, was not a fluent speaker of the English language; instead, he spoke his native German, and was for this ridiculed by his British subjects. During his reign, the powers of the monarchy found themselves diminished; the modern system of government by a Cabinet underwent development. During the later years of his reign, actual power was held by a de facto Prime Minister, Sir Robert Walpole.