Britain's first Prime Minister was Sir Robert Walpole, who served from 1721 to 1742. He was the longest-serving Prime Minister in British history and is often referred to as the 'Father of the Modern British Cabinet'. Walpole was a Whig politician who was instrumental in establishing the political party system in Britain. He was also responsible for introducing many reforms, including the establishment of the Bank of England and the introduction of the window tax. Walpole is remembered for his successful efforts to maintain peace with Britain's European neighbours during his tenure.