Saint Francis of Assisi, possible Pilgrim
The tip to
http://www.saint-jacques.info/francois.html posted in reply to an early question is a good one.
If you'd like to believe the legend (copied below), complete with its little miracles and visions, about St. Francis tasking a poor charcoal-maker to build two convents,
>> La même tradition se retrouve à Santiago, sans doute née avec le
>> premier couvent franciscain de la ville : saint François, pendant son
>> séjour, reçut l'hospitalité d'un pauvre charbonnier, nommé Cotolay.
>> La demeure de celui-ci s'élevait sur une colline qui dominait deux
>> petites vallées, le « Val de Dieu » et le « Val d'Enfer ».
then the mention of a place called Val de Dios indicates a journey along the coastal road, rather than across the pass at Roncesvalles. Thus, Francis would have walked across Provence and Gascony, rounded the Pyrenees near the present day border crossing at Irun, and continued along the coast. This route would have taken him through Oviedo, where there were numerous holy relics to venerate, and then probably inland through Fonsagrada and Lugo to join the Camino Francés near Palas de Rei.
The problem with this legend is that while there was a pre-existing Pre-Romanesque church in Val de Dios (still standing), it was built something over three centuries earlier in the time of Alfonso III the Great. There is also a monastery in Val de Dios connected with the little church and founded more or less in the time (erly 1200's) St. Francis would have passed through there, but the monastic order connected with it was the Cistercians, not the Franciscans.
So there's enough reality in the legend to support the idea that St. Francis passed along the Camino del Norte, but the period is a blank spot in the contemporary biographies of the Saint. The best answer anyone can give to your question is, perhaps. I wouldn't disbelieve the story simply because there's an accretion of unlikely legend about it, but neither would I be upset if it all turned out to be the invention of someone's imagination. A connection between Francis and Compostela doesn't lend necessary support to the validity of the Pilgrimage, or to the truth of what we know about the life of the Saint himself.
So that's about it. Buen Camino.
Alan