Which preposition to use with janina

in Occurrences 2%

It was the headquarters of Essad Pasha, defender of Janina in the last war, and division commander in this sector of the front.

on Occurrences 1%

These vilayets are Scutari and Janina on the Adriatic; Kossovo and Monastir, adjoining them on the east; next Saloniki, embracing the centre of the area; and finally Adrianople, extending from the Mesta River to the Black Sea.

Which preposition to use with  janina