A more thorough explanation:

Denelage is another term for Danelaw, which was a system of rules introduced by the Danes during their invasions of England in the ninth century. This system of law was primarily maintained in the midland and eastern counties where the invasions occurred.

The counties in England where the Danish law was enforced primarily in the ninth and tenth centuries are also referred to as denelage. The term lex Danorum is also used to describe this system of law.

For example, during the reign of King Edgar to Edward the Confessor, Danelaw was the prevailing law in the regions where the Danes had conquered. Edward the Confessor compiled a uniform law that included some Danelaw components.

The Danish invasions of the ninth century subjected the eastern parts of the island to new Scandinavian influences. Where the Danes conquered, their ‘Danelaw’ prevailed. The very word ‘law’ is believed to have been given to the English language by the Danes.

These examples illustrate how the term denelage is used to describe the system of law introduced by the Danes during their invasions of England and the regions where this law was enforced.