Which preposition to use with commissars

of Occurrences 3%

The Bolshevik Commissar of Kushva, acting on this principle, succeeded in a short time in raising a formidable opposition amongst the workmen in the surrounding districts.

in Occurrences 1%

The breaking off of these negotiations caused great annoyance to the Soviet Government at Moscow, and they ordered their commissars in Ussurie to use the forces which had been organised under American protection to attack their protectors, which they at once proceeded to do.

of Occurrences 1%

The manager stuck to his post during the battle of Perm, and by a judicious distribution among the Bolshevik Commissars of the surplus roubles of the Tsar remaining in his possession got them out of the works without damage.

Which preposition to use with  commissars