Exchange of the Princesses (1729) in the context of José I

Dom Joseph I (Portuguese: José Francisco António Inácio Norberto Agostinho; 6 June 1714 – 24 February 1777), known as the Reformer (Portuguese: o Reformador), was King of Portugal from 31 July 1750 until his death in 1777. Among other activities, he was devoted to hunting and the opera. His government was controlled by Sebastião José de Carvalho e Melo, 1st Marquis of Pombal, who implemented new laws, modernized the economy and Portuguese society, marking Joseph's reign as a time of modernization of Portugal.

The third child and second son of King John V, Joseph became his father's heir as an infant when his older brother, Pedro, Prince of Brazil, died. In 1729, he married Infanta Mariana Victoria, the eldest daughter of Philip V of Spain. They had four daughters: Maria, Mariana, Doroteia, and Benedita.