The system dates back to 16 December 1811, when
Napoleon designated a number of
routes impériales (imperial highways). First-class routes were numbered from 1 to 14; all began at
Paris, radiating out in a
clockwise manner. Route 1 ran from Paris north to
Calais, and is still the general path of
route nationale 1. Second-class routes, from 15 to 27, did the same, while third-class routes from 28 to 229 provided less major connections. During the
Bourbon Restoration, in 1824, these routes were renamed
routes royales (royal highways) and modified. Route 3, Paris to
Hamburg via
Soissons,
Reims and
Liège, was renumbered to 31 and 51, and the subsequent routes were shifted down by one. Routes 19 and 20 were completely outside the post-Napoleon France, and so 21 to 27 became 18 to 24. In 1830 the highways were renamed
routes nationales. In the 21st century, the French Government has downgraded many of the former routes nationales, such as the
N7 from Paris to the
Côte d'Azur, transferring responsibility for them to the
départements. ==List of routes nationales==