1538

January–June

• February 24 – Treaty of Nagyvárad: Peace is declared between King Ferdinand and the Turks. John Zapolya is recognized as King of Hungary, while Ferdinand retains the northern and western parts of the Kingdom, and is recognized as heir to the throne.
• April 26 – Battle of Las Salinas: Almagro is defeated by Francisco Pizarro, who then seizes Cuzco.
• June 18 – Truce of Nice: Peace is declared between Emperor Charles V and Francis I of France.

July–December

• August 6 – Bogotá, Colombia is founded by Gonzalo Jiménez de Quesada.
• September 28 – Battle of Preveza: The Turkish fleet of Suleiman the Magnificent under the command of Barbarossa Hayreddin Pasha defeats the Holy League of Emperor Charles V under the command of Andrea Doria.
• October 28 – The first university of the New World, the Universidad Santo Tomás de Aquino, is founded.
• November 30
  • Sucre, Bolivia is founded under the name Ciudad de la Plata de la Nueva Toledo.
  • Byland Abbey is dissolved.

Undated

• Michelangelo starts work on the Piazza del Campidoglio (Capitoline Hill).
• Bisham Abbey is dissolved.
• The first in a decade-long series of severe famines and epidemics sweep central and southeastern China during the Ming Dynasty, made worse by a previous decision in 1527 to cut back on the intake of grain quotas for granaries.
• During the Ming Dynasty of China, a tsunami floods over the seawall in Haiyan County of Zhejiang province, inundating the agricultural crop fields with saltwater and ruining many acres of crops. This drives up the price of foodstuffs and many are forced to live off of tree bark and weeds (as one Wang Wenlu stated in his writing of 1545).

Births

• January 10 – Louis of Nassau, Dutch general (d. 1574)
• January 15 – Maeda Toshiie, Japanese samurai and warlord (d. 1599)
• March 25 – Christopher Clavius, German mathematician and astronomer (d. 1612)
• April 26 – Gian Paolo Lomazzo, Italian painter (d. 1600)
• October 2 – Saint Charles Borromeo, saint and cardinal of the Roman Catholic Church (d. 1584)
• October 31 – Caesar Baronius, Italian cardinal and historian (d. 1607)
• November 16 – Saint Turibius of Mongrovejo, Spanish Grand Inquisitioner and missionary Archbishop of Lima (d. 1606)
• date unknown
  • François de Bar, French scholar (d. 1606)
  • Diane de France, illegitimate daughter of Henry II of France (d. 1619)
  • Kitsuno, concubine of Japanese daimyo (d. 1566)
  • Ashikaga Yoshihide, Japanese shogun (d. 1568)

Deaths

• January 8 – Beatrice, Duchess of Savoy (b. 1504)
• February 12 – Albrecht Altdorfer, German painter (b. c. 1480)
• April 3 – Elizabeth Boleyn, Countess of Wiltshire (b. 1480)
• April 4 – Elena Glinskaya, Regent of Russia
• May 8 – Edward Fox, English churchman (b. 1496)
• May 22 – John Forrest, English Franciscan friar (martyred) (b. 1471)
• June 30 – Charles of Egmond, Duke of Guelders (b. 1467)
• July 8 – Diego de Almagro, Spanish conquistador (b. 1475)
• September 14 – Henry III of Nassau-Breda, Baron of Breda (b. 1483)
• October 20 – Francesco Maria I della Rovere, condottiero (b. 1490)
• November 22 – John Lambert, English Protestant martyr (burned at stake)
• date unknown – Pierre Gringore, French poet and playwright (b. 1475)