The first settlement in what is today Redditch was the establishment of an abbey, called Bordesley Abbey, on November 22nd 1138 by a couple of dozen white robed monks. These were Cistercian monks and the Abbey quickly flourished including an important commercial activity involving water powered mills and fish ponds. So important it became that it took a leadership role in the creation of several other abbeys in Stoneleigh, Flaxley and Gloucestershire, and also one in Gruchet le Valasse in France. The abbey there is still standing and the town has recognized the link with Redditch by naming one of its squares after it. Cistercian abbeys were all of identical design, so it gives us an idea of what Bordesley Abbey may have looked like today.
Bordesley Abbey decayed after the black plague and disestablishment during Henry VIII's reign. There is also a claim that what remained of the abbey was destroyed by Oliver Cromwell's cannons during the civil war of 1642-46. Today there are only ruins left. They are adjacent to the National Needle Museum, celebrating perhaps one of Redditch's most important industries historically. Here is an aerial view of the site today, the building at the bottom is the museum, the ruins are at the top left and the ponds at the top right used to be the Cistercian fish farms.
The land around the abbey has a clay-like composition possibly containing iron ore that led, when rain, to the formation of a rivers of red clay. A latin document of the 1200's already refers to the place as "de Rubeo Fossata" (the Red Ditch). Normans also called it Rededich or Rededych. More pictures of the museum and the ruins here.
(Source: Old Redditch voices by Anne Bradford).