Year 1504 (MDIV) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. Events January–June January 1 – French troops of King Louis XII surrender Gaeta to the Spanish, under Gonzalo Fernández de Córdoba. January 21 – After the death of Sten Sture the Elder on December 14 the year before, Svante Nilsson is elected the new Regent of Sweden. January 31 – Treaty of Lyon: France cedes Naples to Ferdinand II of Aragon, who becomes King of Naples as Ferdinand III. February 29 – Christopher Columbus uses his knowledge of a lunar eclipse this night, to convince the indigenous Jamaican people to provide him with supplies. April 1 – English guilds become subject to state control. April 23 – Maximilian I, Holy Roman Emperor, routes troops to Bavaria. July–December September 8 – Michelangelo's sculpture of David is completed in Florence. September 13 – Queen Isabella and King Ferdinand issue a Royal Warrant for the construction of Capilla Real, a Royal Chapel, to be built in Granada. September 22 – Treaty of Blois: Philip I of Castile, Maximilian I and Louis XII agree to terms. October 12 – Isabella I of Castile signs her will and testament. November 7 – Christopher Columbus returns to Spain from his fourth voyage, during which he and his younger son, Ferdinand, explored the coast of Central America from Belize to Panama. November 26 – On the death of Isabella I of Castile, Catholic Queen of Castile and Aragon, the Crown of Castile passes to her daughter Joanna. December 8 (approximate date) – Islamic scholar Ahmad ibn Abi Jum'ah issues the Oran fatwa for Muslims in Spain (1 Rajab 910 AH in Hijri calendar, Gregorian date is approximate). December 24 – Knut Alvsson's rebellion was crushed at Olsborg Castle in Båhuslen. Date unknown Babur besieges and captures Kabul. Islamization of the Sudan region: A Funj leader, Amara Dunqas, founds the Sultanate of Sennar. Sheikh Ahmad, final leader of the Great Horde, is last heard of as a Lithuanian prisoner at Vilnius. Juan de la Cosa begins his first independent voyage, to the Isthmus of Panama. 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