Joseph I (Portuguese José), the Reformer (Port. o Reformador), 25th (or 26th according to some historians) King of Portugal was born in Lisbon, on June 6, 1714. He was the third child of King John V of Portugal and his wife Mary Anne Josepha of Austria. Joseph had an older brother, Peter, but he died at the age of two.

In 1729, Joseph married to a Spanish princess, Marianne Victoria of Borbón, daughter of Philip V of Spain and Elizabeth Farnese, and his elder sister Barbara married to the future Ferdinand VI of Spain. Marianne loved music and hunting, but she was also a serious woman, who disliked the King's affairs and had no problems about talking about them to everybody. Joseph and Marianne had only four daughters - Mary I (who succeeded her father); Mary Anne Frances(1736-1813); Mary Frances Dorothy (1739-1771); Mary Frances Benedicta (1746-1829), who married her nephew crown prince Joseph, son of Queen Mary I, when she was 30.

Joseph was devoted to the Church and the opera. He succeeded to the Portuguese throne in 1750, with 35 years old, and almost immediately placed effective power in the hands of Sebastião José de Carvalho e Mello, the Marquis of Pombal. Indeed the history of Joseph's reign is really that of Pombal himself.

The powerful marquis sought to overhaul all aspects of economic, social and colonial policy to make Portugal a more efficient contender with the great powers of Europe, and thus secure her own middle-power status as a result. A conspiracy of nobles aimed (allegedly) at murdering King Joseph and the marquis gave Pombal the pretext to get rid of his personal enemies, the Távora family, and to expel the Jesuits in September 1759, thus gaining control of public education and a wealth of church lands.

The reign of Joseph was also famous for the great Lisbon earthquake of November 1, 1755, in which around 100,000 people lost their lives. The capital was eventually rebuilt at great cost, and an equestrian statue of King Joseph still dominates Lisbon's main plaza.

With Joseph's death on February 24, 1777 the throne passed to his daughter Mary I and Pombal's iron rule was sharply brought to an end.