The 1240s was a decade of the Julian Calendar which began on January 1, 1240, and ended on December 31, 1249.
Significant people
Fibonacci. Fibonacci sequence and Liber Abbaci
1240s
32 words updated Jun 17, 2026, 11:57 PM
WikiHQWikiHQ32 words updated Jun 17, 2026, 11:57 PM
The 1240s was a decade of the Julian Calendar which began on January 1, 1240, and ended on December 31, 1249.
Fibonacci. Fibonacci sequence and Liber Abbaci