Which preposition to use with illyricum

to Occurrences 1%

Then he decided to leave Gaul and hasten into Macedonia on land through Illyricum to Marcus Brutus, and sent ahead some of the soldiers while he was engaged in finishing some business he had in hand.

with Occurrences 1%

IX.But after the departure of the Liburnian fleet, Marcus Octavius sailed from Illyricum with what ships he had to Salona; and having spirited up the Dalmatians, and other barbarous nations, he drew Issa off from its connection with Caesar; but not being able to prevail with the council of Salona, either by promises or menaces, he resolved to storm the town.

Which preposition to use with  illyricum