Until 1911 the Bourn Brook was the ancient Anglo-Saxon boundary between Worcestershire and Staffordshire (Harborne), and Warwickshire (Edgbaston). The boundaries of the Midland shires were possibly established during the reign of the Danish Kings from 1016-1042 based on the former tribal kingdoms. Physical features were frequently used to identify the boundary of a region or estate. The Hamlet of Bournbrook developed at a crossing point of the Bourn Brook. Potentially it was a meeting place for the nobility of each of the shires. The Bourn Brook, which flows into River Rea near in Cannon Hill Park, is the Ward boundary.