Throughout the first half of the seventeenth century, there continued more or less constant disturbances. There were a number of armed outbreaks of the Kozaks against the Poles in which the Kozaks presented modifications of their essential demand, a constant increase in the number of registered Kozaks. Most of these were finally put down by the Poles under the leadership of Koniecpolski and Potocki and after each new setback the Poles carefully restricted the number of registered Kozaks. More important than that, they worked constantly to weaken the rules about the election of the Kozak hetmans and sought to restrict their choice to the Kozaks of good family, who came of gentry stock. In this way they hoped to drive a wedge between the Kozak officers and the rank and file and thus to prevent the movement from taking a more serious turn. They also arranged to build a fort near the rapids of the Dnyeper, so as to prevent free passage between the Zaporozhian Sich and the rest of the Kozaks. This perpetual conflict seriously weakened Poland, which still declined to take any measures which would either solve the Kozak problem or put the state in a position to defy them. In general the King was more inclined to support or compromise with the Kozaks than were the magnates and the gentry, who usually demanded severe measures against both the Kozaks and the Orthodox, but who were equally against any measure that would carry their policy into effect. It was no more favorable to the Kozaks, for the hetmans were continually forced to sign agreements which they could not and did not wish to carry out, while at the same time no hetman was strong enough to plan and carry through any policy which might allow him to win any real concession from the Poles. The ordinary Kozaks could not secure any permanent improvement in their status, and so there commenced a general exodus of the lesser Kozaks from the Ukraine and the Dnyeper valley to the so-called Slobidshchina, the land of free communes, a region in the neighborhood of Kharkiv but which was under the jurisdiction of Moscow. For years this region was weakly governed for it was still on the border of the Muscovite state and it offered many of the same advantages that Ukraine and the Dnyeper valley had a century earlier.