The south transept of Chester Cathedral served as the ancient parish church of St. Oswald, which originally served the townships of Bache, Croughton, Great Boughton, Newton by Chester and Wervin, and parts of Blacon cum Crabwall, Upton by Chester, and the City of Chester. It also included the ancient parochial chapelry of Bruera: St. Mary. Further afield lay Iddinshall and Hilbre Island. The parish in that form perhaps represented the remains of a once much greater Anglo-Saxon unit, together with some outliers added to it only after they became part of St. Werburgh's estates. The parish was termed indifferently St. Oswald's and St. Werburgh's in the 13th century, when the parishioners used the altar of St. Oswald in the abbey nave as their chief place of worship.
A late tradition that the cult of St. Oswald was introduced when the minster was refounded by Æthelflæd of Mercia gains plausibility from the fact that she translated the same saint's remains to Gloucester in 909 after being involved in a military expedition to recover them. A new minster in Gloucester, was renamed St Oswald's Priory in his honour. Æthelflæd, and her husband Æthelred, ealdorman of Mercia, were buried in the priory, and their nephew (and foster son), King Æthelstan, was a major patron of Oswald's cult. Oswald's head was interred in Durham Cathedral together with the remains of Cuthbert of Lindisfarne (a saint with whom Oswald became posthumously associated, although the two were not associated in life; Cuthbert became bishop of Lindisfarne more than forty years after Oswald's death) and other valuables in a quickly made coffin, where it is generally believed to remain, although there are at least four other claimed heads of Oswald in continental Europe.
The parish possessed burial rights in the city and its environs, originally shared only with St Johns, the other early minster church in the city. Besides the churchyard south of the abbey nave, it had by the later 12th century a cemetery outside the Northgate, associated with the chapel of St. Thomas of Canterbury and served by the monks of St. Werburgh's. Its burial rights were guaranteed by agreements with St. John's and by a papal bull in the late 12th and 13th century. Shortly after 1348 the monks removed the congregation to the chapel of St. Nicholas in the south-west corner of the abbey precinct, where the parish continued to worship until 1539, when it moved back to the abbey and the chapel was leased to the city.
St Oswalds bell has an interesting history, it is said to have first been moved to Hilbre Island and then later to Bidston.
What was later the Music Hall was built in about 1300 for Simon de Albo, the abbot of St Werburgh's, Chester. It was originally St Nicolas Chapel. It was used for a period as the church of the parish of St Oswald (who were kicked out of the Cathedral), then closed as a church and conveyed to the Mayor and Assembly of Chester in 1488. In 1545 an upper floor was inserted and it was used as the Commonhall and Wool Hall. The building was used for staging plays from around 1750, then further converted as the New Theatre in 1773 and the Theatre Royal in 1777–78. James Harrison modified it again into a hall for concerts and entertainments in 1854–55, when it was known as the Music Hall. It later became the Music Hall Cinema.
Oswald's father Æthelfrith was a successful Bernician ruler who, after some years in power in Bernicia, also became king of Deira, and thus was the first to rule both of the kingdoms which would come to be considered the constituent kingdoms of Northumbria. It would, however, be anachronistic to refer to a "Northumbrian" people or identity at this early stage, when the Bernicians and the Deirans were still clearly distinct peoples. Oswald was apparently born in or around the year 604, since Bede says that he was killed at the age of 38 in 642.
Æthelfrith, was for years a successful war-leader, especially against the native British, where he took part in the Battle of Chester but was eventually killed in battle around 616 by Raedwald of East Anglia at the River Idle. This defeat meant that an exiled member of the Deiran royal line, Edwin, became king of Northumbria, and Oswald and his brothers fled to the north. Oswald thus spent the remainder of his youth in the Scottish kingdom of Dál Riata in northern Britain, where he was converted to Christianity. He may also have fought in Ireland during this period of exile.
Cadwallon ap Cadfan, the king of Gwynedd, in alliance with the pagan Penda of Mercia, killed Edwin of Deira in battle at Hatfield Chase in 633. Oswald's brother Eanfrith became king of Bernicia, but he was killed by Cadwallon in 634 (or 633) after attempting to negotiate peace. Subsequently, Oswald, at the head of a small army (possibly with the aid of allies from the north, the Scots and/or the Picts), met Cadwallon in battle at what became known as Heavenfield, near Hexham. The battle was a decisive victory for Oswald, and it was likely that the Welsh losses were substantial.
The monastery of Lindisfarne was founded around 634 by Irish monk Saint Aidan, who had been sent from Iona off the west coast of Scotland to Northumbria at the request of King Oswald. The priory was founded before the end of 634 and Aidan remained there until his death in 651. Oswald had also given the island of Lindisfarne to Aidan as his episcopal see. Aidan achieved great success in spreading the Christian faith. Bede mentions that Oswald acted as Aidan's interpreter when the latter was preaching, since Aidan did not know English well and Oswald had learned Irish during the exile of his youth.
Oswald was King of Northumbria from 634 until his death, 5 August 641/642 when he was killed in the Battle of Maserfield fighting against Penda of Mercia. Penda, a pagan, was probably the most powerful of the Anglo-Saxon rulers of the time, laying the foundations for the Mercian Supremacy over the Anglo-Saxon Heptarchy. Penda was also the paternal grandfather of Werburgh. Bede prefers to focus on Oswalds role in the development of the church and does not inform us why he was (possibly) near Oswestry when he fought his final battle. Oswald's body was cut into pieces, and his head and arms mounted on poles; the parts were retrieved in the next year by his brother and successor Oswiu. Although Oswald could be interpreted as a martyr for his death in battle, Bede puts a clear emphasis on Oswald being saintly as a king. A saint who was also a king would have had the highest ranking relics of any native.
Following the battle, Deira, in the southern part of Northumbria, chose a king of its own, Oswine, while Bernicia in the north (which had been dominant, with Oswald, a member of the Bernician royal line, ruling both Bernicia and Deira prior to Maserfield) was ruled by Oswald's brother Oswiu. Thus the battle led to the internal weakening and fracturing of the Northumbrian kingdom, a situation which lasted until after the battle of the Winwaed. After seven years of peaceful rule, Oswiu declared war on Oswine. Bede blames Oswiu for the troubles. Oswine refused to engage in battle, instead retreating to Gilling and the home of his friend, Earl Humwald. Humwald betrayed Oswine, delivering him to Oswiu's soldiers by whom Oswine was put to death in 651. Oswiu's unchallenged domination of Britain lasted only a short time, ending when a revolt (c. 656) among the Mercians established Penda's son Wulfhere (Werburgh's father) as their king. The most likely cause for this was the death of Peada, supposedly poisoned by his wife, Oswiu's daughter Eahlflæd. A negotiated settlement appears to have been preferred on both sides to prevent war.
In 664 at the synod of Whitby, Oswiu accepted the usages of the Roman Church. Bede writes that the dispute was brought to a head by Oswiu's son Ealhfrith, who had adopted Roman usages at the urging of Wilfrid. Bishop Colman resigned his see at Lindisfarne in protest soon afterward and Wilfred eventually succeeded him, but moved his Episcopal seat to York. His rule was short-lived however. Claiming there is no-one in Britain with the authority to consecrate him, he left for France and was enthroned by the Archbishop of Paris. Wilfred liked the Frankish Archiepiscopal court so much that he delayed his return and King Oswiu decided to appoint Abbot Chad of Lastingham (later St Chad) as Bishop of York instead.
Like his brother Oswald, Oswiu was made a saint but largely forgotten and never developed a strong cult. Bede writes that Oswiu was fluent in the Old Irish language and Irish in his faith - a negative for Bede. Even the murdered Oswine had a stronger cult than Oswiu. Bede's writings elevated Oswald above both these others with Osiwu losing out perhaps because of the amount of treachery he and his supporters (including his wife) had engaged in, and Oswald gaining because he supported Aiden.