1521

January 22: The Diet of Worms parliament is opened by Emperor Charles V in the German city of Worms.

Template:C16 year in topic 1521 (MDXXI) was a common year starting on Tuesday of the Julian calendar, the 1521st year of the Common Era (CE) and Anno Domini (AD) designations, the 521st year of the 2nd millennium, the 21st year of the 16th century, and the 2nd year of the 1520s decade.

Events

File:Scrisoarea-lui-neacsu-din-campulung.jpg

Neacșu's letter, the oldest surviving document written in Romanian has the oldest appearance of the word "Rumanian"

January–March

January 3 – Pope Leo X excommunicates Martin Luther, in the papal bull Decet Romanum Pontificem.<ref>Template:Cite book</ref>
January 22 – Charles V, Holy Roman Emperor, opens the Diet of Worms in Worms, Germany.<ref>Template:Cite book</ref>
January 27 – Suleiman the Magnificent suppresses a revolt by the ruler of Damascus, Janbirdi al-Ghazali.<ref>Template:Cite book</ref>
February 2 – The Nydala Abbey Bloodbath takes place at Nydala Abbey, Sweden; the abbot and many monks are murdered by Danes.<ref>Template:Cite book</ref>
March 6
- Ferdinand Magellan makes the first European contact with Guam,<ref>Template:Cite book</ref> most likely landing in Tumon.<ref>Template:Cite journal</ref>
- Martin Luther is summoned to appear before the Diet of Worms.<ref>Template:Cite book</ref>
March 16 – Ferdinand Magellan reaches the Philippines, in eastern Samar.<ref>Template:Cite book</ref>
March 31 – The First Mass in the Philippines is held.<ref>Template:Cite book</ref>

April–June

April 7
- Ferdinand Magellan arrives at Cebu.<ref>Template:Cite book</ref>
- Martin Luther preaches an inflammatory sermon to students at Erfurt, while on his way to Worms.<ref>Template:Cite book</ref>
April 16–18 – Martin Luther is examined before Emperor Charles V and the Diet of Worms, where he refuses to recant his writings and allegedly proclaims, "Here I stand", regarding his belief in the Bible alone, as the standard of Christian doctrine.
April 23 – Revolt of the Comuneros – Battle of Villalar: Castilian royalists defeat the rebels.<ref name="REV">Template:Cite book</ref> Juan López de Padilla, Francisco Maldonado, and Juan Bravo are executed the following day as the leaders of the rebels.
April 26 – Martin Luther leaves Worms and disappears for around a year<ref>Template:Cite web</ref> – he is rumored to be murdered, but is actually in hiding at the Wartburg castle.<ref>Template:Cite book</ref>
April 27 – Battle of Mactan: Ferdinand Magellan is killed in the Philippines when he confronts Lapulapu, the chief of the island.<ref>Template:Cite journal</ref>
April or May – Battle of Tunmen in Tuen Mun (present-day Hong Kong): The Ming Dynasty navy defeats the Portuguese navy<ref>Template:Cite book</ref> (arguably the first Sino-European battle in world history).
May 17 – Edward Stafford, 3rd Duke of Buckingham, is executed for treason in Tower Hill.<ref name="ES">Template:Cite journal</ref>
May 20 – At the Battle of Pampeluna in Italy, and alliance of forces from French and the Kingdom of Navarre forces defeat those of Spain.<ref>Template:Cite book</ref>
May 25 – The Diet of Worms ends when Charles V, Holy Roman Emperor issues the Edict of Worms, declaring Martin Luther an outlaw and banning his literature.<ref>Template:Cite book</ref>
May 27 – After death of his cousin, Jiajing, Prince Zhu Houcong became the new Ming dynasty Emperor of China, taking the imperial name of the Emperor Jiajing becomes the new.<ref>Template:Cite book</ref>
June 25 – Suleiman the Magnificent begins the siege of Belgrade.
June 29 or 30 – The oldest surviving dateable document written primarily in the Romanian language: Neacșu's letter, written by a trader from Câmpulung, to Johannes Benkner, the mayor of Brașov, warning that the Ottoman Empire is preparing its troops to cross into Wallachia and Transylvania; the script used is Romanian Cyrillic.
June 30 – Battle of Esquiroz: French forces under André de Foix, fighting for the exiled King of Navarre Henri d'Albret, are defeated by the Spanish, and forced to abandon their attempt to recover Henri's kingdom.<ref>Template:Cite book</ref>