NEW YORK, NY.- It was good to be the king in ancient Babylonia, unless, of course, an eclipse occurred during his reign. Such an event foretold revolt, rebellion, defeat in war, loss of territory, plague, drought, crop failure, locust attacks or even the king’s death. Should the last omen be foretold, the king would go into hiding and a substitute — say, a prisoner or a simpleton — would be installed until the danger had passed. To appease the gods, someone would have to die, so upon the return of the true king, the substitute would be executed.

The people of Mesopotamia in the second millennium B.C. attached a prophetic significance to celestial events. Eclipses were generally understood to be angry messages from the gods. “The reading of omens was how the Babylonians made sense of the world,” said Andrew George, an Assyriologist and emeritus professor at the University of London whose translation of the epic of Gilgamesh is one of the most widely read.

George led a study published this month in the Journal of Cuneiform Studies that deciphered a set of four tablets covered in cuneiform script and have been held by the British Museum since the late 1800s. The clay slabs most likely came from Sippar, a prosperous city on the banks of the Euphrates, in what is now Iraq. They are dated to about 1894 B.C. to 1595 B.C.

The artifacts, a compendium of Babylonian astrologers’ observations of lunar eclipses, reveal a series of ominous predictions about the deaths of kings and the destruction of civilizations. “The purpose of the omen texts was to figure out what the gods wanted to communicate, good or bad, so as to take action to avoid any trouble ahead,” George said.

The idea was that earth and sky were mirror images, so happenings in the heavens had counterparts on land. Which is why an eclipse of the sun or moon signaled that a great terrestrial figure would, in some way, be eclipsed: For instance, a king would die. “It is possible that this theory arose from the coincidence of an eclipse and a king’s death — that is, actual experience early in Mesopotamian history,” George said. “But it is also possible that the theory was developed entirely by analogy. We cannot know.”

The Babylonians saw portents everywhere, which accounts for numerous references in the tablets to the flight and behavior of birds, the patterns made by dropping oil into water, smoke rising from incense burners and encounters with snakes, pigs, cats and scorpions. There are 61 predictions on the newly translated tablets that vary from warnings about natural disasters (“An inundation will come and reduce the amount of barley at the threshing floors”) to unnatural chaos (“Lions will go on a rampage and cut off exit from a city”). The most poignant predictions describe desperation in time of famine: “People will trade their infant children for silver.”

Performing the appropriate ritual, the Babylonians believed, could stop, or at least mitigate, a dire omen and alter the future. If an omen was especially threatening, a priest would conduct an oracular inquiry by ritually sacrificing a sheep and reading its entrails. The main internal organs examined were the liver, the lungs and the colonic spiral. “Basically, the diviner was looking for anything unusual,” George said, including “deformations, absence of features, doubling of features, splits and grooves in surfaces.”

Typically, features that appeared on the right side were considered to be positive and on the left, to be negative, though what constituted right and left differed in each region of Babylonia. The priest would then tally the results, which, if ambiguous, might necessitate another sacrifice.

Arguably, all divination at the state level in Babylonia became a tool to regulate the king’s behavior and a way those close to the ruler exercised political power over him. “One suspects that some kings were more superstitious, and thus more susceptible to manipulation by diviners than others,” George said. “Since lunar eclipses were, by their nature, ill portents for the king, the omens attached to them spoke to his deepest anxieties about what catastrophes might happen to him and his people.”

The substitute-king ritual is associated with the Neo-Assyrian period, which lasted from about 900 B.C. to 612 B.C., though it may have been practiced later as well. “Omen specialists in Babylon likely performed the rite for Alexander the Great when he fell severely ill in the city, and subsequently died,” said Troels Pank Arboll, an Assyriologist at the University of Copenhagen.

He praised the new research, in which he was not involved, for its precision and rigor. “It provides the first full treatment of these complicated texts,” Arboll said.

Most of the more than 100,000 Mesopotamian tablets in the British Museum’s collection remain undeciphered, if not uncataloged. More omens may surely wait in the archives.

“There are too many tablets and not enough Assyriologists,” George said, adding: “Only a tiny fraction of the tablets are on display. One hundred or so public galleries stuffed with cuneiform tablets would excite very few visitors.”

This article originally appeared in The New York Times.