Ermine Street was the Saxon name of a road in England that ran from London to Lincoln and York. It was named for a group called the Earningas, who inhabited an area that is now in Cambridgeshire. It is now sometimes called the Old North Road. It followed the route of an earlier, longer Roman road, begun in 43 AD, that ran from Chichester to York.
The section of Ermine Street from London to Royston, Hertfordshire is now part of the A10. At this point it crosses the Icknield Way. The section from Huntingdon to Colsterworth is now part of the A1.