In a nutshell:
Camino Primitivo was the first Camino route to Santiago de Compostela in the 9th century when most of Spain was under Moorish control.
This was the route followed by King Alfonso II "the Chaste" in the 9th century from the city of Oviedo, in Asturias. Oviedo is the starting point of the Original Way, but this was also the route traditionally followed by pilgrims from further afield in Northern Spain and Europe.The first section of the Camino Primitivo is one of the most challenging of all the Camino routes.