(18 May) The Great Siege of Malta began. The siege lasted for nearly four months and on 11 September 1565, the Ottoman fleet led by Suleiman the Magnificent had to withdraw. The Ottomans should have taken the city, but Malta’s defenders and the arrival of a relief army of Spanish soldiers turned the tide.

(18 May) Persian astronomer, mathematician, and poet, Omar Khayyam, was born in Nishapur (now in Iran). He is known primarily as a scientist, particularly as an astronomer and mathematician who contributed to the Jalali calendar. While in the West, he is widely known for his Rubaiyat (quatrains).