622 CE
A year defined by the Hijra, the migration of the Prophet Muhammad and his followers from Mecca to Medina, an event of such importance that it marks the beginning of the Islamic calendar.
Culture & Society
- The Prophet Muhammad and his followers emigrated from Mecca to Yathrib, later known as Medina, in an event called the Hijra, escaping persecution by the Quraysh tribe.
- In Medina, Muhammad established the first organized Muslim community, or ummah, and negotiated the Constitution of Medina, a compact that defined relations among the Muslim emigrants, Medinan converts, and the city's Jewish tribes.
- The Hijra was later designated as the starting point of the Islamic calendar by Caliph Umar ibn al-Khattab, reflecting its significance as the founding moment of the Muslim political community.
- The estimated world population was approximately 210 million.
Climate & Environment
- Atmospheric carbon dioxide concentration was approximately 277 parts per million, as later confirmed by ice core analysis.