Which preposition to use with sustainer

of Occurrences 5%

By his majesty's conduct, my lords, the reputation of our country is now raised to its utmost height; we are now considered as the arbiters of empire, the protectors of right, the patrons of distress, and the sustainers of the balance of the world.

through Occurrences 1%

Khadijah, his companion and sustainer through so many troublous years, died in 619, having borne with him all his revilings and discouragements, his source of strength even when there appeared no prospect of the abatement of his hardships, much less for the success of his cause.

Which preposition to use with  sustainer