Which preposition to use with alexius

in Occurrences 1%

With great astuteness, and at the cost of large gifts, Alexius in like manner freed the neighborhood of his capital from the invading multitudes.

on Occurrences 1%

He was ready, he said, to be the friend of Alexius on equal terms; but he would not declare himself to be his man.

Which preposition to use with  alexius