The Constitution was originally legalized after a referendum on 6 December 1978 and was signed by King Juan Carlos
on 27 December 1978. The signing of the Constitution marked the perfection of the Spanish transition to democracy after the death of
the former Head of State, Francisco Franco, in 1975. This led to the country undergoing a series of political and historical changes that transformed the Francoist regime into a democratic state. The Constitution states that the King of Spain is the head of state. However, the king's function is simply symbolic and doesn´t have any executive power.
The separation of powers
is implicit stated throughout the Constitution, which says that all
people have the right to decide the representatives who will occupy the General Cuts, compuond of the Congress of Deputies and the Senate; both share the legislative power.