Streoneshalh was established by the King of Northumbria, an Anglo-Saxon ruler called Oswy. Under his instructions, Lady Hilda was made the abbess of Hartlepool Abbey, while the niece of Edwin (the first Christian king of the area) was elected as the founding abbess. St. Hilda's convent was Celtic in style, which has been confirmed by the fascinating archaeological remains. Men and women lived separately, but worshipped together, as was customary in double monasteries of the time. St. Hilda was renowned for her incredible wisdom, which was combined with a humble, genuine interest in the common folk of the day. This led to a huge amount of respect for this saint, causing even royal leaders to consult with her for advice. She died at only 66 years of age.
There are several theories regarding the origin of the name, Streoneshalh, but none have been confirmed as being absolutely correct. When the Danes invaded between 867 and 870, they desolated Streoneshalh; a condition that lasted some two centuries following the destruction.
The second monastery was established by Reinfrid, one of William the Conqueror's soldiers who became a monk and was handed the ruined monastery of St. Peter. This monastery followed the Benedictine rule and lasted until 1540, when King Henry VIII destroyed it in response to the Dissolution of the Monasteries. Interestingly, when Reinfrid acquired the monastery from William de Percy, de Percy also gave him the parish church of St. Mary, six dependent chapels, and several mills.