The Middle Angles were incorporated into the wider kingdom of Mercia, apparently well before the reign of
Penda (c.626–655), who evidently felt safe enough to locate his base in their territory. He placed his eldest son,
Peada, in charge of the Middle Angles as sub-king.
Bede specifies the Middle Angles as the target of a four-man Christian mission accepted by Peada, who converted to Christianity, partly in order to wed Alchflaed, the daughter of King
Oswiu of Northumbria. This mission arrived in 653 and included St
Cedd. Peada's conversion and acceptance of baptism in Northumbria possibly indicates a continuing sense of disunity or local particularism within Mercia. It is unlikely that Peada could have pursued so different a course from his father, at the strategic and political centre of the Mercian kingdom, without local support among the Middle Angles. , Apostle to the Middle Angles|thumb|left|upright Following the defeat and death of
Penda (655), and the murder of
Peada himself (656) at the instigation of his Northumbrian wife, Oswiu was able to dominate Mercia. He appointed one of the missionary priests, the Irish
Diuma, bishop of the Middle Angles and the Mercians. Bede makes much of the fact that a shortage of priests compelled the appointment of one bishop to two peoples. This seems to indicate that the Middle Angles, while a central part of the Mercian kingdom, were clearly distinguished from the Mercians proper, a designation that seems to have been reserved for people settled further North and West. Diuma apparently died among the Middle Angles after a short but successful mission. His successor, Ceollach, another Irish missionary, returned home after a short time, for reasons that Bede does not specify. He was followed in turn by
Trumhere and
Jaruman.
Wulfhere, another son of Penda, continued to base his rule over Mercia among the Middle Angles, with the royal centre at
Tamworth. In 669, after the death of Jaruman, he requested that the archbishop of Canterbury send a new bishop. This was
Chad, brother of Cedd. According to Bede, Chad was designated "bishop of the Mercians and Lindsey people". In this case there is no doubt that the Middle Angles are subsumed into the category of the Mercians. The ecclesiastical centre for the entire vast region was established in Middle Angle territory, for Wulfhere donated land a short distance away from Tamworth, at
Lichfield, to allow Chad to establish a monastery. It seems that the distinctions between the peoples within Mercia were gradually fading and that it was possible for them all to be described as Mercians. It is less clear whether this more accurately reflects the understanding of Chad's own time, or of Bede's, in the early 8th century. ==Political and ecclesiastical centre==