Fait général: 1155 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 1155 is the Stirling number of the second kind S(11,9).
Culture générale: 1155 is an unremarkable number.
Date historique: February 28th is the day in 1914 that the Autonomous Republic of Northern Epirus is proclaimed in Gjirokastër, by the Greeks living in southern Albania.