Mafra National Palace in the context of Mafra, Portugal

Dom John V (Portuguese: João Francisco António José Bento Bernardo; 22 October 1689 – 31 July 1750), known as the Magnanimous (o Magnânimo) and the Portuguese Sun King (o Rei-Sol Português), was King of Portugal from 9 December 1706 until his death in 1750. His reign saw the rise of Portugal and its monarchy to new levels of prosperity, wealth, and prestige among European courts.

John V's reign saw an enormous influx of gold into the coffers of the royal treasury, supplied largely by the royal fifth (a tax on precious metals) that was received from the Portuguese colonies of Brazil and Maranhão. John spent lavishly on ambitious architectural works, most notably Mafra Palace, and on commissions and additions for his sizable art and literary collections. Owing to his craving for international diplomatic recognition, John also spent large sums on the embassies he sent to the courts of Europe, the most famous being those he sent to Paris in 1715 and Rome in 1716.

Manuel Caetano de Sousa (1738–1802) was a Portuguese architect. He studied architecture under his father Tomás Caetano. He worked in the late Baroque and rococo style of architecture. On the death of Mateus Vicente de Oliveira he became architect to the royal family and was appointed architect in charge of public works and raised to the rank of an artillery colonel.

His works included the church of the "Incarnation, of S. Domingos" and the Bemposta Chapel. In his capacity as Royal architect he worked on various of the many royal palaces, most notably being responsible for the great library at Palace of Mafra and the east wing of the Palace of Queluz, which is today that part of the palace reserved for a visiting head of state. He also designed the tower of the Royal Chapel. In 1795, to honour of the birth of Dom António, 4th Prince of Beira, de Sousa designed an amphitheatre for use as a bull ring constructed in the Praça do Comércio in Lisbon.