Year 1523 (MDXXIII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. Events January–June January 20 – Christian II is forced to abdicate as King of Denmark and Norway. May – The Ningbo Incident: Two rival trade delegations from Japan feud in the Chinese city of Ningbo, resulting in the pillage and plunder of the city. June 3 – Santhome Church was established by Portuguese explorers over the tomb of Saint Thomas the Apostle in Chennai, India. June 6 – Gustav Vasa is elected king of Sweden, finally establishing the full independence of Sweden from Denmark, which marks the end of the Kalmar Union. This event is also traditionally considered to be the establishment of the modern Swedish nation. July–December c. July – Martin Luther's translation of the Pentateuch into German () is published. July 1 – Jan van Essen and Hendrik Vos become the first Flemish Lutheran martyrs, burned at the stake by Roman Catholic authorities in Brussels. July 7 – Wijerd Jelckama, a Frisian warlord and military commander, is executed in Leeuwarden, ending the Frisian rebellion fought by the Arumer Black Heap. July 25 - In what is now Mexico, the conquistador Gonzalo de Sandoval founds the city of Colima. September 22 – Spanish conquest of Nicaragua: Agreement for an expedition by conquistadores into Nicaragua. November 19 – Following the death of Pope Adrian VI, the Medici cardinal is elected 219th pope as Clement VII. Date unknown The Ming dynasty Chinese navy captures two Western ships with Portuguese breech–loading culverins aboard, which the Chinese call a fo–lang–ji (Frankish culverin). According to the Ming Shi, these cannons are soon presented to the Jiajing Emperor by Wang Hong, and their design is copied in 1529. Franconian War: The Swabian League destroys 23 robber baron castles. In northern Italy, a French army tries to recover Milan but fails due to an offensive by Spanish, Imperial and English troops. Births January 29 – Enea Vico, Italian engraver (d. 1567) February 1 – Francesco Abbondio Castiglioni, Italian Catholic cardinal (d. 1568) February 13 – Valentin Naboth, German astronomer and mathematician (d. 1593) February 20 – Jan Blahoslav, Czech writer (d. 1571) March 14 – Helena Magenbuch, German pharmacist (d. 1597) March 17 – Giovanni Francesco Commendone, Italian Catholic cardinal (d. 1584) March 21 – Kaspar Eberhard, German theologian (d. 1575) April 5 – Blaise de