[1][3][4] The event was marked by the presentation of Gil Vicente's Visitation Play or the Monologue of the Cowherd (Auto da Visitação ou Monólogo do Vaqueiro) in the queen's chamber.

The young prince was sworn heir to the throne in 1503, the year his youngest sister, Isabella of Portugal, Empress Consort of the Holy Roman Empire between 1527 and 1538, was born.

Some historians also argue this was one of the main reasons that John later became fervently religious, giving him the name of the Pious (Portuguese: o Piedoso).

On 19 December 1521 John was crowned king in the Church of São Domingos in Lisbon, beginning a thirty-six-year reign characterized by extensive activity in internal and overseas politics, especially in relations with other major European states.

The large and far-flung Portuguese Empire was difficult and expensive to administer and was burdened with huge external debt and trade deficits.

In the Atlantic, where Portuguese ships already had to withstand constant attacks of privateers, an attempted expansion of the French colonial empire in Brazil, France Antarctique, created yet another front.

In the first years of John III's reign, explorations in the Far East continued, and the Portuguese reached China and Japan; however, these accomplishments were offset by pressure from a strengthening Ottoman Empire under Suleiman the Magnificent, and especially in India, where attacks became more frequent.

To pay for it, John III abandoned several strongholds in North Africa: Safim, Azemmour, Ksar es-Seghir and Arzila.

However, the intermarriage of these closely related royal families may have contributed to the poor health of John's children and future King Sebastian of Portugal.

John III remained neutral during the war between France and Spain but stood firm in fighting the attacks of French privateers.

Through his links to Portuguese humanists such as Luís Teixeira Lobo, Erasmus dedicated his Chrysostomi Lucubrationes to John III of Portugal in 1527.

He had been enthusiastically endorsed by Diogo de Gouveia, his teacher at the Collège Sainte-Barbe, and advised the king to draw the youngsters of the newly formed Society of Jesus.

John III was persuaded to establish the Inquisition in Portugal by pressure from neighboring Castile and reports that New Christians had failed to properly renounce Judaism.

[18][19] The activities of the Inquisition extended from book censorship, repression and trial for divination, witchcraft and bigamy, as well as the prosecution of sexual crimes, especially sodomy.

[22] In John III's time, trade between the Portuguese and Africans was extremely intense in feitorias such Arguim, Mina, Mombasa, Sofala or Mozambique.

[25] John III refused to abandon all of the Portuguese North African strongholds, but he had to make choices based on the economic or strategic value of each possession.

The fortresses of Ceuta, Tangiers and Mazagan were strengthened "to face the new military techniques, imposed by the generalization of heavy artillery, combined with light fire weapons and blades".

[26] John III's court jester was João de Sá Panasco, a black African, who was eventually admitted to the prestigious Order of Saint James based on his service in the Conquest of Tunis (1535).

[27][28] Before the reign of John III, the Portuguese had already reached Siam (1511), the Maluku Islands (1512), the Chinese littoral (1513), Canton (1517) and Timor (1515).

From India, John III imported an amazing variety of spices, herbs, minerals, and fabrics; from Malacca, exotic woods and spice; from Bengala, fabrics and exotic foodstuffs; from Alexandria and Cairo, exotic woods, metals, minerals, fabrics, and boullion; and from China, musk, rhubarb and silk in exchange for gromwells, pearls, horses from Arabia and Persia, non-worked silk, silk embroidery threads, fruits of the date palm, raisins, salt, sulphur and many other goods.

The hostility of many Indian kingdoms and alliances between sultans and zamorins with the intent of expelling the Portuguese made it necessary for the Europeans to establish a sovereign state.

Goa became a starting point for the introduction of European cultural and religious values in India, and churches, schools and hospitals were built.

Because the Portuguese established themselves in Macau, Chinese commercial relations and the silver trade with Japan were improved under John III's rule.

During the reign of King John III the Portuguese Empire established itself in South America with the foundation of the twelve Captaincy Colonies of Brazil (from 1534 onwards).

During John III's rule, after the initial colonization, Portuguese explorers intensified the search for brazilwood and began the cultivation of sugarcane, which was well suited to the climate of Brazil and especially around Recife and Bahia.

Since Brazil lacked a large native population and the ones who lived there weren't adapted to the strenuous work required in the plantation fields, the Portuguese colonists began importing African slaves to strengthen the workforce present in the territory.

Like his predecessors John III used the style "El-rei" (the king) followed by "Dom" (abbreviated to D.), a mark of high esteem for a distinguished Christian nobleman.

The official style was the same used by his father Manuel I: "Dom João, by the grace of God, King of Portugal, of the Algarves, of either side of the sea in Africa, Lord of Guinea, & of the Conquest, Navigation, & Commerce of Ethiopia, Arabia, Persia, & India" (Dom João, por graça de Deus, Rei de Portugal, e dos Algarves, d'aquém e d'além mar em África, Senhor da Guiné, e da Conquista, Navegação, & Comércio da Etiópia, Arábia, Pérsia, & Índia).