Mariana Victoria of Spain ( ; 31 March 1718 -- 15 January 1781 ) was an `` Infanta of Spain '' by birth and was later the Queen of Portugal as wife of King Joseph I .
Mariana Victoria of Spain ( 31 March 1718 -- 15 January 1781 ) sometimes Maria Anna Victoria was an `` Infanta of Spain '' by birth and was later the Queen of Portugal as wife of King Joseph I .