The Prime Minister's Office is a ministry of the Government of Sri Lanka. It provides the administrative and institutional framework for the exercise of the duties and responsibilities vested in the Prime Minister of Sri Lanka. From 1947 to 1978 it was the most powerful office within the government. However, after the creation of the executive presidency in 1978 the post of Prime Minister became more or less nominal and functions as a deputy to the President. Since 1960 the office has been based at Sirimathipaya Mansion, Sir Ernest de Silva Mawatha (formerly Flower Road), Colombo at the former residence of legendary philanthropist Sir Ernest de Silva.