 It is a Grade II* listed building.The church of St Mary is situated in the old township of Rumworth on high ground above the Church Brook, the Saxon "Kirkbroke", which flows through Deane Clough to the River Croal.St Mary, or "St Mariden" was a chapel of ease of St Mary in Eccles before becoming the mother church of the ancient ecclesiastical parish of Deane which was formed from the northern part of the parish of Eccles and takes its name from Deane Clough, the narrow wooded valley close to the west of the church.