March 16 – In what is now India's Kerala state, a second invasion of the Portuguese-supported Kingdom of Cochin by the Zamorin of Calicut takes place, beginning a war that lasts until July 3.
May 24 – Le Hien Tong, Emperor of Vietnam, dies after a reign of six years and is succeeded by his 15-year-old son Le Tuc Tong.
June 17 – Rao Bika Rathore, ruler of the Kingdom of Bikaner in India, dies after a reign of 32 years. For a brief time Bika is succeeded by his elder son Nara, but Nara quickly dies and Nara is succeeded by his brother Lunkaran.
June 28 – After being marooned in Jamaica for six months, Christopher Columbus and his men are rescued by a Spanish ship.
July 3 – The siege of Cochin in India by the invading forces of Calicut ends as the Portuguese and Cochin defenders defeat the invaders. Calicut loses 5,000 dead in battle and another 13,000 to disease, while Cochin and Portugal sustain minimal losses.
July 7 – At the age of 16, Lê Túc Tông becomes the new Emperor of Vietnam (Dai Viet) after the death of his father, Lê Hiến Tông, but serves for only six months before dying.
July 20 – Pope Julius II issues an order reforming the official coinage of the Papal States, raising the silver content of the carlino coin to four grams. In that the Pope was formerly Giuliano della Rovere, the new coin is called the giulio in his honor and features the coat of arms of the della Rovere family.
In Florence, Leonardo da Vinci and Niccolò Machiavelli become involved in a scheme to divert the Arno River, cutting the water supply to Pisa to force its surrender: Colombino, the project foreman, fails to follow da Vinci's design, and the project is a major failure.