Mariana Victoria of Spain was an Infanta of Spain by birth and was later the Queen of Portugal as wife of King Joseph I. She acted as regent of Portugal in 1776–1777, during the last months of her husband's life and as advisor to her daughter, Maria I of Portugal, in her reign.

Dom Joseph I, known as the Reformer, was King of Portugal from 31 July 1750 until his death in 1777. Among other activities, Joseph was devoted to hunting and the opera. His government was controlled by Sebastião José de Carvalho e Melo, 1st Marquis of Pombal.