The cause of Mazeppa's quarrel with the Czar was this: He was one day paying a visit to his majesty, and, while seated at table, Peter began to complain of the lawless and ungovernable character of the Cossacks, and to propose that Mazeppa should introduce certain reforms in the organization and discipline of the tribe, with a view of bringing them under more effectual control. It is probable that the reforms which he proposed were somewhat analogous to those which he had introduced so successfully into the armies under his own more immediate command.
Mazeppa opposed this suggestion. He said that the attempt to adopt such measures with the Cossacks would never succeed; that the men were so wild and savage by nature, and so fixed in the rude and irregular habits of warfare to which they and their fathers had been so long accustomed, that they could never be made to submit to such restrictions as a regular military discipline would impose.
Peter, who never could endure the least opposition or contradiction to any of his ideas or plans, became quite angry with Mazeppa on account of the objections which he made to his proposals, and, as was usual with him in such cases, he broke out in the most rude and violent language imaginable. He called Mazeppa an enemy and a traitor, and threatened to have him impaled alive. It is true he did not really mean what he said, his words being only empty threats dictated by the brutal violence of his anger. Still, Mazeppa was very much offended. He went away from the Czar's tent muttering his displeasure, and resolving secretly on revenge.
Soon after this Mazeppa opened the communication above referred to with the King of Sweden, and at last an agreement was made between them by which it was stipulated that the king was to advance into the southern part of the country, where, of course, the Cossacks would be sent out to meet him, and then Mazeppa was to revolt from the Czar, and go over with all his forces to the King of Sweden's side. By this means the Czar's army was sure, they thought, to be defeated; and in this case the King of Sweden was to remain in possession of the Russian territory, while the Cossacks were to retire to their own fortresses, and live thenceforth as an independent tribe.