Maria I of Portugal.
Maria I (1735 - 1816) was Queen of Portugal from 1777 to her death in 1816. She was the first queen regnant in Portuguese history.
Maria was the eldest of the four daughters of King Joseph I. In 1760 she married her father's younger brother, Prince Peter. Upon her accession on 24 February 1777 her husband became King Peter III, but though the two theoretically ruled jointly, Maria exercised the actual power. After the outbreak of the Trans-Oceanic War in the spring of 1795, Maria feared that Spain's alliance with France and Austria represented a threat to Portugal. Her government concluded a treaty of alliance with Prime Minister Sir Charles Jenkinson of Great Britain. When Jenkinson declared war on France, a contingent of British troops arrived in Portugal to defend against a possible Spanish invasion.