During December 1650 Charles and the Scottish government reconciled with the Engagers who had been purged from it and Highland chiefs who had been excluded by their refusal to sign the Covenant. These competing factions were poorly coordinated and it was not until the late spring of 1651 that they were fully integrated into the Scottish army. In January 1651 the English attempted to outflank the Scottish-held choke point of Stirling by shipping a force across the Forth of Firth, but this was unsuccessful. In early February the English army advanced against Stirling, then retreated in dreadful weather; Cromwell himself fell ill.