Which preposition to use with hyrcania

as Occurrences 1%

On one occasion he selected the history of Felixmarte of Hyrcania as his course of reading during a visit.]

at Occurrences 1%

These historians state that at this time Jericho was captured and destroyed and that a part of the Jewish people were transported to the province of Hyrcania at the south of the Caspian Sea.

Which preposition to use with  hyrcania