There is no specific date as to when the office of Prime Minister first appeared as the role was not created, but rather evolved over a period of time through a merger of duties.
Modern historians have not managed to agree who the first prime minister of Spain was, but Francisco Martínez de la Rosa was the first prime minister recognized by a constitutional law (the Spanish Royal Statute of 1834).
Due to the gradual evolution of the post, the title has been applied to early prime ministers retroactively.
There is no specific date when the office of prime minister first appeared as the role was not created, but rather evolved over a period of time through merger of duties.
Later, the reforms introduced by Phillip V in the 1710s established several secretaries of state for specific government areas, and the secretary of State for Foreign Affairs (Secretario de Estado y del Despacho de Estado) was eventually known as the First Secretary of State due to its de facto role as primer minister.