Ælfflæd Queen of Mercia was born to King Offa of Mercia and Cynethryth Queen Mercia.
On 29 Sep 792 Æthelred I of Northumbria (age 30) and Ælfflæd Queen of Mercia were married. She by marriage Queen Northumbria. She the daughter of King Offa of Mercia and Cynethryth Queen Mercia. He the son of Æthelwald Moll King of Northumbria.
Anglo-Saxon Chronicle. and Osred, who had been king of the Northumbrians, returning home after his exile, was apprehended and slain, on the eighteenth day before the calends of October. His body is deposited at Tinemouth. [her husband] Ethelred (age 32) this year, on the third day before the calends of October, took unto himself a new wife, whose name was Elfleda.
On 18 Apr 796 [her husband] Æthelred I of Northumbria (age 34) died.
Paternal Family Tree: Iclingas
Great x 4 Grandfather: Pybba King Mercia 590-610
Great x 3 Grandfather: Eowa King Mercia -642
Great x 2 Grandfather: Osmod Iclingas
Great x 1 Grandfather: Eanulf-
GrandFather: Thingfrith-
Father: King Offa of Mercia
Mother: Cynethryth Queen Mercia