Signed and dated: “D.os Anto de Siqueira inv. e Pintou 1803”.
The theme of this painting is the military manoeuvres conducted at Campo do Quadro, near Azambuja, towards the end of 1798. The Prince Regent is said to have been delighted to watch these military exercises that took place close to Lisbon and involved 6,700 soldiers commanded by the Lieutenant-General João de Ordaz e Queirós, who is portrayed as the most advanced figure in the group of three officers on horseback in the lower left corner of the painting.
There are thirteen charcoal and chalk preparatory studies for this painting at the Museu Nacional de Arte Antiga in Lisbon.
King João VI (1767-1826), the third son of Queen Maria I and King Pedro III, was born in Lisbon and married Princess Carlota Joaquina, the daughter of Carlos IV of Spain, in 1785. On the death of his brother José, the Prince of Brazil, he became the queen’s direct heir in 1788. From 1792 onwards, he was made Prince Regent due to Queen Maria I’s incapacity for government. In 1818, he was acclaimed king, two years after his mother’s death in Rio de Janeiro.