1630 followed by 1631
1630 (MDCXXX) was a common year starting on Tuesday of the Gregorian calendar and a common year starting on Friday of the Julian calendar, the 1630th year of the Common Era (CE) and Anno Domini (AD) designations, the 630th  year of the 2nd millennium, the 30th  year of the 17th century, and the  1st   year of the 1630s decade. As of the start of 1630, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.Events
January–March
January 2 – A shoemaker in Turin is found to have the first case of bubonic plague there as the plague of 1630 begins spreading through Italy.
January 5 – A team of Portuguese military advisers to China's Ming dynasty government arrive at Zhuozhou. Led by Gonçalo Teixeira Corrêa, and accompanied by interpreter João Rodrigues, the group begins training the troops of Governor Sun Yuanhua in using modern cannons.
January 11 – Otto III and his brother William Augustus, both, Dukes of Brunswick-Harburg, sell their rights to inherit rule of Brunswick-Lüneburg to Prince Christian for in return of his payment of their debts of more than 150,000 thaler.
January 13 – In China, General Yuan Chonghuan is invited to an audience with the Chongzhen Emperor and is arrested on charges of collusion with the enemy. Yuan is executed by the slow death on September 22.
January 18 – Nicolò Contarini is elected as the new Doge of the Republic of Venice and spends most of his time fighting a bubonic plague epidemic, but dies in office on April 2, 1631.
February 22 – Native American Quadequine introduces popcorn to English colonists.
March 3 – A fleet sent by the Dutch West India Company captures Recife from the Portuguese, establishing Dutch Brazil.
March 9 – The 1630 Crete earthquake occurs.
March – Fedorovych Uprising: Zaporozhian Cossacks rebel against the Polish–Lithuanian Commonwealth, and occupy a large part of modern-day Ukraine. After a number of indecisive skirmishes with a Polish army sent to pacify the region, the Treaty of Pereyaslav is signed, ending the uprising.