For 10 points, name this Franco-endorsed attack on a Basque town, commemorated by a Picasso painting.
In 1967, Roman Herzog apologized for this event, whose casualties were exacerbated by the fact that Mondays are typically market days for the city in question. Incidentally sparing the Casa de Jontas and an ancient oak stump and carried out by Junker and Heikel bombers, it was a joint operation by the Italian air force and the Luftwaffe. For 10 points, name this Franco-endorsed attack on a Basque town, commemorated by a Picasso painting.
In 1967, Roman Herzog apologized for this event, whose casualties were exacerbated by the fact that Mondays are typically market days for the city in question.
bombing of Guernica [or obvious equivalents]