Which preposition to use with aga

of Occurrences 4%

He had 'an escort of the Aga of Hassia's best Arab horsemen.'

with Occurrences 3%

and thirtie miles there is anothet castle like vnto the abouesayd kept by an Aga with fourtie men or thereabout.

in Occurrences 1%

He came with me to Winkelsteg, remained three days, made Berthold gamekeeper, and arranged that he should forthwith marry Aga in our church.

Which preposition to use with  aga