jan 9, 1742 - Robert Walpole is made Earl of Orford, and resigns as First Lord of the Treasury and Chancellor of the Exchequer, effectively ending his period as Prime Minister of Great Britain.[1] On his formally relinquishing office five days later, he will have served 20 years and 314 days as Prime Minister, the longest single term ever, and also longer than the accumulated terms of any other British Prime Minister