In July 917,

Æthelflæd Æthelflæd, Lady of the Mercians ( 870 – 12 June 918) ruled Mercia in the English Midlands from 911 until her death. She was the eldest daughter of Alfred the Great, king of the Anglo-Saxon kingdom of Wessex, and his wife Ealhswith. Æthe ...

launched her first offensive foray and selected the fortress at

Derby Derby ( ) is a city and unitary authority area in Derbyshire, England. It lies on the banks of the River Derwent in the south of Derbyshire, which is in the East Midlands Region. It was traditionally the county town of Derbyshire. Derby g ...

as her target. At that time the local ruler had probably joined with the armies from Northampton and Leicester in a number of raids to attack Mercia. Aethelfled took advantage of the weakened burh and successfully assaulted the town in July 917; the whole region subsequently being annexed into English Mercia. Derby was the first of Five Danelaw Burgh's to be defeated by Aetheflead's Army in the "liberation of the Danelaw" along with, Leicester, Lincoln, Nottingham and Stamford. The '' Anglo-Saxon Chronicle'' says that in 917 "Aethelflaed Lady of the Mercians, with God's help, before

Lammas Lammas Day (Anglo-Saxon ''hlaf-mas'', "loaf-mass"), also known as Loaf Mass Day, is a Christian holiday celebrated in some English-speaking countries in the Northern Hemisphere on 1 August. The name originates from the word "loaf" in reference ...

obtained the borough that is called Derby. With all that belonged to it. There were also killed four thegns who were dear to her inside the gates" The Danes may well have established their military headquarters on the former Roman fort of Derventio. This rectangular fort would have given the burh the equivalent of ''c.'' 500 hides. Survey work was carried out at the Little Chester Site between 1986 and 1990 and notes "Refurbishments to the defences in the late Saxon period may be associated with the Danish incursions of the 9th century and Little Chester could be the site of the battle of 917" The battle itself is not well attested to. Even the 4 thegnes who were lost during the battle are unknown. For the battle to have been lost "within the Walls of the Burgh" implies storming of the settlement - thought to have been around 1300 people at the time. The Vikings had camped at nearby

Repton Repton is a village and civil parish in the South Derbyshire district of Derbyshire, England, located on the edge of the River Trent floodplain, about north of Swadlincote. The population taken at the 2001 Census was 2,707, increasing to 2,8 ...

in 874, and abandoned it a year later after suffering significantly from disease during their stay (leading to the discovery of a grave containing 245 bodies). By 878 Viking Raids had seized the small settlement at Derby ( at the time called by its Saxon name Northworthy)http://www.derbyshireuk.net/derby_history.html from a Weakened Mercia, setting the stage for the 917 /918 campaign to recapture the five boroughs.

References

917 Battles involving the Vikings 10th century in England 910s conflicts {{England-battle-stub