Osthryth (also Osthryd, Osthryda, Ostreð, Ostrida, Ostryð; † 697 ) was the king of Æthelred the 7th century queen of the Anglo-Saxon Kingdom of Mercia woman.
Osthryth was a daughter of King Oswiu of Northumbria and his wife Eanflæd.
In the earlier research, sometimes the by John Leland (1506-1552) was applied theory represented Osthryth would first marriage possibly with Eanhere, the king of Hwicce been married. Your children should have been Osric and Oswald. This theory is rejected by modern historians.
At an unknown date married Osthryth the King Æthelred of Mercia. Her sister Ealhflæd was around the year 653 with Peada, king of the means fishing and brother Æthelreds married. The purpose of this marriage policy was to improve the strained relations for decades between Northumbria and Mercia. From the compound Ceolred, later King Mercia went ( 709-716 ) out. Maybe Æthelred and Osthryth founded the monastery Beardaneu ( Bardney ) in Lindsey; It is certain that they promoted it. In the year 679 there was a battle between man Osthryths Æthelred on one side and her brothers Ecgfrith, king of Northumbria, and Ælfwine, the sub- king of Deira, on the other hand, fell in Ælfwine. One of Archbishop Theodore of Tarsus, Archbishop of Canterbury, mediated Wergeldzahlung could restore peace. In 680, Æthelred granted to the monastery Medeshamstede (now Peterborough ) duty exemption and endowed it with lands. Osthryths signatures are under two document parts: Ego Ostrich regina Æðelredi registered prompto animo hiis annuo. ("I, Osthryth, Queen of King Æthelred, voice inclined to heart " ) and Ic Osðriðe. Æðelredes cwen ("I, Osthryth, Æthelreds Queen "). The fact that their signature is still before the papal legate and several bishops, indicates a high position at the court, even though the certificate is probably a later forgery. In another deed Æthelreds she was mentioned by name. The torso of her uncle, King Oswald, who had Lindsey once annexed and had fallen 642 at the Battle of Maser Field, Osthryth was probably interred in the 670er 680er or years in Bardney Monastery and promoted his cult. In the year 697 Osthryth was murdered by Mercian nobleman, possibly because they had represented to stubbornly Northumbrian interests. She was buried in Bardney Abbey. In Bardney a cult developed around them, but whose backgrounds remain unclear. Maybe it was because of her murder as a martyr. More likely, however, that they, together with Æthelred, probably this monastery was after his abdication monk and later abbot, were revered because of their importance for the Abbey.