Ermine Street is a major Roman road in England that ran from London (Londinium) to Lincoln and York (Eboracum). The Old English name was Earninga Strǣt (1012), named after a tribe called the Earningas, who inhabited a district later known as Armingford Hundred, around Arrington, Cambridgeshire, and Royston, Hertfordshire. "Armingford", and "Arrington" share the same Old English origin. The original Celtic and Roman names for the route remain unknown. It is also known as the Old North Road from London to where it joins the A1 Great North Road near Godmanchester.

Londinium, also known as Roman London, was the capital of Roman Britain during most of the period of Roman rule. Most twenty-first century historians think that it was originally a settlement established shortly after the Claudian invasion of Britain, on the current site of the City of London around 47–50 AD, but some defend an older view that the city originated in a defensive enclosure constructed during the Claudian invasion in 43 AD. Its earliest securely-dated structure is a timber drain of 47 AD. It sat at a key ford at the River Thames which turned the city into a road nexus and major port, serving as a major commercial centre in Roman Britain until its abandonment during the 5th century.