Today marks the anniversary of the 1937 bombing of Guernica, Spain. In itself, the atrocity is significant enough, being one of the first instances of modern saturation bombing. The event looms particularly large in the cultural imagination, however, due to Pablo Picasso’s famed anti-war painting Guernica (1937), an association that continues to keep the tragedy in the spotlight, almost 80 years after the fact.

Thus, reviewing a new book about the bombing for the New York Review of Books, Picasso biographer John Richardson turns up the following macabre new insight:

In Gernika, 1937: The Market Day Massacre, the historian Xabier Irujo reveals the hitherto unknown fact that the destruction of the historic Basque town of Guernica was planned by Nazi minister Hermann Göring as a gift for Hitler’s birthday, April 20. Guernica, the parliamentary seat of Biscay province, had not as yet been dragged into the Spanish civil war and was without defenses. Logistical problems delayed Göring’s master plan. As a result, Hitler’s birthday treat had to be postponed until April 26.

The full Richardson review of Irujo’s tome is well worth reading—though it can only by a stretch of the imagination be called a “review” since the above opening passage is almost the only reference to the essay’s purported subject.

Richardson, instead, offers a loose collection of fascinating Guernica trivia. He speculates, for instance, that one of the figures in the painting is actually a portrait of Picasso’s lost sister Conchita. He also recounts a contemporaneous, but more-or-less unrelated episode, where Picasso pointedly rejected the opportunity to shake the hand of Italian Futurist impresario—and fascist—F.T. Marinetti, by declaring, “You seem to forget that we’re at war.”

Poster for Gernika, directed by Kolbo Serra

The twisted forms of Picasso’s painting are said to have been inspired by a news report from the British war correspondent George Steer. As it so happens, Steer’s life has also inspired a new movie, Gernika, which debuted today at the Malaga Film Festival, in Picasso’s hometown. Actor James D’Arcy plays a version of Steer, reimagined, for some reason, as an American war correspondent named Henry.

The trailer is below: