The bombers roared in low on a sunny afternoon. Unopposed by antiaircraft fire or fighter defenses, they pounded away for almost 3½ hours, Heinkel-111s in the lead, followed by ponderous Junkers-52 trimotors. As fighter planes wove in and out, strafing people on the ground, the bombers unloaded some 100,000 lbs. of high-explosive, fragmentation and incendiary bombs on a small Basque town in the green hills of northern Spain. When the bombers left, a town had been smashed to rubble, but a symbol was bornstill evoked for many by Pablo Picasso's best-known and most terrifying canvas.
The date was April 26,...