In the 1250s, the King gave out numerous grants of land along the frontier in Ireland to his supporters, creating a buffer zone against the native Irish. The local Irish kings began to suffer increased harassment as English power increased across the region. These lands were in many cases unprofitable for the barons to hold and English power reached its zenith under Henry for the medieval period. In 1254, Henry granted Ireland to his son, Edward, on condition that it would never be separated from the Crown.