1421

1421 commonly refers to the calendar year 1421 CE or to the four-digit number itself.

In historical terms, the year 1421 occurred during the Ming dynasty in China. It is associated with the period when the capital was moved from Nanjing to Beijing, a shift linked to the reign of the Yongle Emperor. The move marked a major administrative change, and Beijing began to serve as the imperial seat during this era.

In modern popular history, 1421 is the title of a controversial book, 1421: The Year China Discovered the World, written by Gavin Menzies and published in 2002. The book argues that Chinese fleets reached the Americas and circumnavigated the globe before European explorers. Its theories are not widely accepted by mainstream historians, who criticize the evidence and methodologies used and point to a lack of corroborating primary sources.

As a number, 1421 is an integer. Its prime factorization is 7 squared times 29 (1421 = 7^2 × 29). It is an odd number and lies between the years 1420 and 1422. In Roman numerals, it is written as MCDXXI.