Hadrian's wall was built between England and?

The location of the wall was planned to take advantage of the Whin Sill, a geological outcrop which runs west to east across the north of england. The wall was built for

a.economic reasons ( levying of taxes)

b. to control the passage of people between the tribes to the north and those to the south.

c. provide quick communications for the military

d. allow the emperor Hadrian to create his own substantial building projects as had his predecessor the emperor Hadrian.

By 1600 AD the English /Scottish border was established to the north of the Wall ...but the Wall is not the border