António, Prior of Crato (sometimes called The Determined, The Fighter or The Independentist), was a grandson of King Manuel I of Portugal and claimant of the Portuguese throne during the 1580 dynastic crisis. According to some historians, he was King of Portugal as António I of Portugal for 33 days in 1580. After the crowning of Philip II of Spain as King of Portugal, António claimed the throne until 1583. He was a disciple of Bartholomew of Braga.
On 19 July 1580, António was proclaimed King of Portugal in Santarém which was followed by popular acclamation in several locations of the country. However, he governed in Continental Portugal for only 20 days, culminating in his defeat in the Battle of Alcântara by the Spanish Habsburg armies led by Fernando Álvarez de Toledo, Duke of Alba on 25 August.
After the above event, he attempted to rule Portugal from the island of Terceira, in the archipelago of the Azores, where he established an opposition government that lasted until 1583, and where he even minted coin — a typical act of sovereignty and royalty. His rule was recognized only in the Azores where his supporters, such as Ciprião de Figueiredo and Violante de Canto, were able to organize a resistance. Meanwhile, on the continent and in the Madeira Islands, power was exercised by Philip II, who was recognized as official king the following year by the Portuguese Cortes of Tomar.
During his last days, António lived as a private gentleman on a small pension given by King Henry IV of France. He died in Paris on 26 August 1595, and was buried in the middle of the choir of the convent church of the Franciscan Observantists (Cordeliers).