Wigstan
Wigstan( died c.840 AD), also known as Saint Wystan, was the son of Wigmund of Mercia and Ælfflæd, daughter of King Ceolwulf I of Mercia.
Ælfwynn
Ælfwynn was the ruler of Mercia for a few months in 918, following her mother's death on 12 June 918.
She was the daughter of Æthelred, ruler of English Mercia, and Æthelflæd( styled The Lady of Mercia).
The" Anglo- Saxon Chronicle" states that she was" deprived of all control in Mercia, and was led into Wessex three weeks before Christmas".
Her accession was the only example of rule passing from one woman to another in the early medieval period in the British Isles.
Oswald, king of the Hwicce
Oswald was a brother of Osric, King of Anglo- Saxon kingdom of Hwicce, a sub-kingdom of Mercia in England.
In a problematic charter, possibly from 679, Oswald and his brother Osric were described as thegns( they are actually referred to as nepotes- usually translated as nephews or grandsons, but here probably meaning step- sons) of Æthelred, King of Mercia.
Osthryth
Osthryth (died 697), queen of the Mercians, was the wife of King Æthelred and daughter of King Oswiu of Northumbria and his second wife Eanflæd.
She probably married Æthelred before 679 and was murdered by the nobles of Mercia.
Osthryth was not the first of her family to become a Mercian queen.
Her sister Alhflæd had married Peada, King of South Mercia 654-656.
After the death of Peada, who was allegedly murdered with Alhflæd's connivance, and possibly Osthryth's as well, she retreated to Fladbury in Worcestershire, to judge both from the place-name, which means "stronghold of Flæde", and from its subsequent history: sometime in the 690s Æthelred granted Fladbury to Oftfor, Bishop of Worcester, to re-establish monastic life there; however, this grant was later contested by Æthelheard, son of Oshere, who maintained that Æthelred had no right to give Fladbury away, as it had been the property of Osthryth.
Æthelheard claimed it as her kinsman and heir.
Æthelred and Osthryth loved and favoured Bardney Abbey in Lincolnshire.
Osthryth placed there the bones of her uncle Oswald of Northumbria, who was venerated as a saint.
It is clear from this story that Osthryth played a part in promoting the cult of St Oswald.
Many years later she persuaded Oswald's widow Cyneburh to take the veil.
Osthryth had to contend with major conflicts of loyalty.
In 679 her brother Ecgfrith of Northumbria fought a battle against Æthelred, in which Ecgfrith's brother Ælfwine was killed.
Bede tells us that he was "a young man of about eighteen years of age and much beloved in both kingdoms, for King Æthelred had married his sister."
The murder of Osthryth in 697 by Mercian nobles is unexplained in the sources that mention it.
Ann Williams attributes it to the hostility between the Mercians and the Northumbrians, while D. P. Kirby suggests that it may have been revenge for her sister's alleged involvement in Peada's murder.
H. P. R. Finberg speculates that she and her kinsman Oshere were suspected of trying to detach the kingdom of the Hwicce from Mercian overlordship.
Osthryth was buried at Bardney Abbey.
Osthryth was probably the mother of Æthelred's son, Ceolred, king of Mercia from 709 to 716.
Ælfflæd of Mercia
Ælfflæd was a daughter of Offa of Mercia and Cynethryth.
She may have witnessed a charter with her father, mother, and brother Ecgfrith in the 770s.
She certainly witnessed a charter in 787 with her mother, father, brother, and two sisters; here she is described as" virgo" —unmarried.
It is possible that she was the daughter of Offa whose proposed marriage to Charles the Younger caused a dispute between Charlemagne and Offa in around 789–790.
In 792 she married Æthelred I of Northumbria at Catterick.
Here she is described as" queen", which has suggested to some historians that she had been previously married, and to a king, perhaps to one of Æthelred's predecessors.
Beornwulf of Mercia
Beornwulf( died 826) was King of Mercia( roughly the Midlands of England) from 823 to 826.
His short reign saw the collapse of Mercia's supremacy over the other kingdoms of the Anglo- Saxon Heptarchy.
Cynethryth
Cynethryth(" Cyneðryð"; died after AD 798) was a Queen of Mercia, wife of King Offa of Mercia and mother of King Ecgfrith of Mercia.
Cynethryth is the only Anglo- Saxon Queen consort in whose name coinage was definitely issued.
Æthelric, king of the Hwicce
Æthelric was a king of the Hwicce and son of Oshere; it is possible that he reigned jointly with Æthelheard, Æthelweard, and Æthelberht.
He is known from charters.
In 692 he witnessed a charter of Æthelred, King of Mercia S 75, together with Æthelheard, Æthelweard, and Æthelberht, and in 693 the four brothers witnessed a charter issued by their father Oshere S 53 In 706( S 1174), he granted land with consent of Cenred, King of Mercia; then in 736( S 89), as" Æthilric subregulus", he witnessed a charter of Æthelbald, King of Mercia; and in an undated charter( S 94), he received a grant himself from the same king.
His kinsman thegn Osred received a grant in 743 from king Æthelbald in charter S 99.
Æthelred of Mercia
Æthelred (died after 704) was King of Mercia from 675 until 704.
He was the son of Penda of Mercia and came to the throne in 675, when his brother, Wulfhere of Mercia, died.
Within a year of his accession he invaded Kent, where his armies destroyed the city of Rochester.
In 679 he defeated his brother-in-law, Ecgfrith of Northumbria, at the Battle of the Trent: the battle was a major setback for the Northumbrians, and effectively ended their military involvement in English affairs south of the Humber.
It also permanently returned the kingdom of Lindsey to Mercia's possession.
However, Æthelred was unable to re-establish his predecessors' domination of southern Britain.
He was known as a pious and devout Christian king, and he made many grants of land to the church.
It was during his reign that Theodore, the Archbishop of Canterbury, reorganized the church's diocesan structure, creating several new sees in Mercia and Northumbria.
Æthelred befriended Bishop Wilfrid of York
when Wilfrid was expelled from his see in Northumbria; Æthelred made Wilfrid Bishop of the Middle Angles during his exile and supported him at the synod of Austerfield in about 702, when Wilfrid argued his case for the return of the ecclesiastical lands he had been deprived of in Northumbria.
Æthelred's wife, Osthryth, was a daughter of King Oswiu, one of the dominant 7th-century Northumbrian kings.
Osthryth was murdered in unknown circumstances in 697, and in 704 Æthelred abdicated, leaving the throne to Wulfhere's son Coenred.
Æthelred became a monk at Bardney, a monastery which he had founded with his wife, and was buried there.
Ceolred, who was Æthelred's son (though apparently not by Osthryth), became king after Coenred; it is also possible that Æthelred had another son named Ceolwald who was briefly king before Ceolred.
Æthelred, Lord of the Mercians
Æthelred, Lord of the Mercians( or Ealdorman Æthelred of Mercia; died 911) became ruler of English Mercia shortly after the death of its last king, Ceolwulf II in 879.
His rule was confined to the western half, as eastern Mercia was then part of the Viking- ruled Danelaw.
Æthelred's ancestry is unknown.
He was probably the leader of an unsuccessful Mercian invasion of Wales in 881, and soon afterwards he acknowledged the lordship of King Alfred the Great of Wessex.
The alliance was cemented by the marriage of Æthelred to Alfred's daughter Æthelflæd.
In 886 Alfred took possession of London, which had suffered greatly from several Viking occupations; as it had traditionally been a Mercian town, he handed control to Æthelred.
In 892 the Vikings renewed their attacks, and the following year Æthelred led an army of Mercians, West Saxons and Welsh to victory over a Viking army at the Battle of Buttington.
He spent the next three years fighting them alongside Alfred's son, the future King Edward the Elder.
At some time in the decade 899 to 909, Æthelred's health may have declined, and Æthelflæd may have become the effective ruler of Mercia.
After Æthelred's death, Æthelflæd ruled as Lady of the Mercians until her own death in 918.
The couple's only child, a daughter called Ælfwynn, then ruled briefly until deposed by her uncle, King Edward.

Question: Who is the stepchild of Æthelred Of Mercia?
Answer: Oshere