Located in a fertile valley, Bonampak is near a small tributary of the Río Lacanjá, with protective hills to one side. The earliest evidence of human occupation at Bonampak are ceramics dated to A.D. 100; it reached its apogee in the Late Classic era (A.D. 600–800). Bonampak has a close and surprisingly amicable relationship with the nearby city of Yaxchilán, just 20 kilometers (12 miles) to the southeast. Bonampak’s most notable leader, Chaan-Muan, was married to the sister of Yaxchilán’s great king Shield Jaguar. The brothers-in-law joined forces in the 7th century in a war against an unknown third city, possibly Sak Tz’i’. The battle is commemorated in a part of Bonampak’s famous murals and lintels. Relatively little else is known about the city, however.

Much more ink has been dedicated to the scandal that arose around the site’s discovery in the 1940s. An American conscientious objector—or draft-dodger, depending on the telling—named Karl Frey was part of a team headed by filmmaker Giles Healy to find and document the ruins, which had been reported to archaeologists 40 years prior but never explored. The two had a falling out and the expedition was abandoned; later, in 1946, Frey succeeded in reaching the site, but evidently missed the murals. Healy made the trip several months later, discovered the murals—even the local Lacandón people seemed not to have known of their existence—and made headlines with his startling find.

Frey spent years trying to convince the world he was the true discoverer, to no avail. He formed part of an ill-advised exploration team organized by the Mexican Fine Arts Institute in 1949—a joint Carnegie Institute and INAH exploration had already gone and returned with detailed maps and drawings—during which he drowned in the Río Lacanjá, reportedly trying to save a fellow team member after their canoe capsized.