The
Republic of Ireland Act 1948 (No. 22 of 1948) is an Act of the
Oireachtas (parliament) which declared that
Ireland may be officially described as the Republic of Ireland, and vested in the
President of Ireland the power to exercise the executive authority of the state in its external relations, on the advice of the
Government of Ireland. The Act was signed into law on 21 December 1948 and came into force on 18 April 1949, Easter Monday, the 33rd anniversary of the beginning of the
Easter Rising.