The county was officially shired in 1586 in the reign of Elizabeth I from the northern portion of Westmeath, but English control was not fully established until the aftermath of the Nine Years' War. County Longford was added to Leinster by James I in 1608 (it had previously been considered part of Connacht), with the county being divided into six baronies and its boundaries being officially defined. The county was planted by English and Scottish landowners in 1620, with much of the O'Farrell lands being confiscated and granted to new owners. The change in control was completed during the Cromwellian plantations of the 1650s. On these lands in County Longford, are the historic ruins of the Coolamber Hall House, which was besieged by one of the Cromwells.