Although some might use 'The Five Boroughs' to refer to New
York City or even Cincinnati, this term really refers to the part of
the old kingdom of Mercia that fell to the Viking invasions of the late
ninth century, and recognized as part of the Danelaw by Alfred the Great
of Wessex. The area under the control of the Five Boroughs is roughly
equivalent to today's East Midlands, bounded by the Humber and Trent,
Watling Street, and the fenlands around The Wash. I'm not sure
how Cheshire fits into this, if at all.
The Danes raided into this area in the eighth and early ninth centuries,
but even as late as 868, settlement was primarily Anglo-Saxon. The
campaign of Ivarr the Boneless changed all of that. The 870 death
of East Anglian king St. Edmund at Ivar's hands gave the Northmen
free rein over the area. After Alfred's treaty establishing the Danelaw,
they gave up raiding for settlement. They fortified four towns:
and built a fifth,
Derby.
Each town and the area around it was under the control of a different
Viking band. The bands' overlords formed a loose confederation under
the nominal overlordship of the kings of Jorvik to the north.
The Five Boroughs became the first step in Wessex's eventual conquest
of the Danelaw. Edward the Elder began his campaign into East
Anglia and the Five Boroughs 914. Derby was the first to
fall, in 917. The same year, Edward's army defeated the East Anglian
army at the Battle of Tempsford, killing king Guthrum II (the mopping
up of East Anglia took another year). Leicester was taken early the
following year, causing the other three boroughs to surrender. By
920, Edward was in control of everything south of the Humber, and even
had the fealty of King Ragnald of Jorvik, as well as everyone else in
Britain.
Wessex's control of the Danelaw was always shaky at best. In 939,
just after the death of Aethelstan, Olaf Guthfrithson, the king of
Dublin, wrested the Five Boroughs and much of the old kingdom of Jorvik
away from Wessex. Aethelstan's son Edmund I recaptured the Five Boroughs
in 942. A revolt in 957 saw the Five Boroughs (and the rest of Britain
north of the Thames) shift their allegiance1 from Edwy the
Fair to his brother Edgar.
The Five Boroughs were among the first territories to fall to Sweyn
Forkbeard and his son Canute in 1013, and were the prize given to
Edmund II Ironside after switching his allegiance from his father Aethelred to Sweyn.
1One suspects that one faction of earls and abbots had
eighteen-year-old Eadwig as their figurehead, and another (led by Eadwig's enemy, Abbot Dunstan) fronted themselves with thirteen-year-old Edgar.