irse por los cerros de Úbeda

Literally: To go off into the hills of Úbeda

Example: “Le preguntaron por el presupuesto y se fue por los cerros de Úbeda.” — They asked him about the budget and he went off on a tangent.

English equivalent: To go off on a tangent

Origin: According to the most commonly repeated version, the phrase dates to the Reconquista, shortly after the Christian victory at the Battle of Las Navas de Tolosa in 1212 opened Andalusia to Christian forces. During the subsequent siege of Úbeda, one of King Fernando III's commanders, Álvar Fáñez, reportedly vanished before the battle began and only reappeared once the city had already fallen. Asked by the king where he had been, he claimed to have gotten lost in the hills (cerros) surrounding Úbeda — an excuse his fellow courtiers took as a transparent cover story, whether for cowardice or a private romantic rendezvous. An alternative, more skeptical account from the 16th-century lexicographer Sebastián de Covarrubias notes simply that the hills around Úbeda wind through the landscape under many different local names, giving rise to a proverb about anyone whose explanation wanders off toward increasingly implausible, far-flung terrain. The phrase's staying power owes much to Cervantes, who used it in Don Quixote, cementing it permanently in the language.