verything has a history, and writers have for thousands of years tried to pull together a universal history of everything. “In earliest times,” the Hellenistic historian Polybius mused, in the second century B.C., “history was a series of unrelated episodes, but from now on history becomes an organic whole. Europe and Africa with Asia, and Asia with Africa and Europe.” For the past hundred years or so, each generation of English-language readers has been treated to a fresh blockbuster trying to synthesize world history. H. G. Wells’s “The Outline of History” (1920), written “to be read as much by Hindus or Moslems or Buddhists as by Americans and Western Europeans,” argued “that men form one universal brotherhood . . . that their individual lives, their nations and races, interbreed and blend and go on to merge again at last in one common human destiny.” Then came Arnold Toynbee, whose twelve-volume “Study of History” (1934-61), abridged into a best-selling two, proposed that human civilizations rose and fell in predictable stages. In time, Jared Diamond swept in with “Guns, Germs, and Steel” (1997), delivering an agriculture- and animal-powered explanation for the phases of human development. More recently, the field has belonged to Yuval Noah Harari, whose “Sapiens” (2011) describes the ascent of humankind over other species, and offers Silicon Valley-friendly speculations about a post-human future.

The appeal of such chronicles has something to do with the way they schematize history in the service of a master plot, identifying laws or tendencies that explain the course of human events. Western historians have long charted history as the linear, progressive working out of some larger design—courtesy of God, Nature, or Marx. Other historians, most influentially the fourteenth-century scholar Ibn Khaldun, embraced a sine-wave model of civilizational growth and decline. The cliché that “history repeats itself” promotes a cyclical version of events, reminiscent of the Hindu cosmology that divided time into four ages, each more degenerate than the last.

What if world history more resembles a family tree, its vectors hard to trace through cascading tiers, multiplying branches, and an ever-expanding jumble of names? This is the model, heavier on masters than on plot, suggested by Simon Sebag Montefiore’s “The World: A Family History of Humanity” (Knopf), a new synthesis that, as the title suggests, approaches the sweep of world history through the family—or, to be more precise, through families in power. In the course of some thirteen hundred pages, “The World” offers a monumental survey of dynastic rule: how to get it, how to keep it, how to squander it.

“The word family has an air of cosiness and affection, but of course in real life families can be webs of struggle and cruelty too,” Montefiore begins. Dynastic history, as he tells it, was riddled with rivalry, betrayal, and violence from the start. A prime example might be Julius Caesar’s adopted son Octavian, the founder of the Julio-Claudian dynasty, who consolidated his rule by entrapping and murdering Caesar’s biological son Caesarion, the last of the Ptolemies. Octavian’s ruthlessness looked anodyne compared with many other ancient successions, like that of the Achaemenid king Artaxerxes II, who was opposed by his mother and her favorite son. When the favorite died in battle against Artaxerxes, Montefiore reports, their mother executed one of his killers by scaphism, “in which the victim was enclosed between two boats while force-fed honey and milk until maggots, rats and flies infested their living faecal cocoon, eating them alive.” She also ordered the family of Artaxerxes’ wife to be buried alive, and murdered her daughter-in-law by feeding her poisoned fowl.

As such episodes suggest, it was one thing to hold power, another to pass it on peacefully. “Succession is the great test of a system; few manage it well,” Montefiore observes. Two distinct models coalesced in the thirteenth century. One was practiced by the Mongol empire and its successor states, which tended to hand power to whichever of a ruler’s sons proved the most able in warfare, politics, or internecine family feuds. The Mongol conquests were accompanied by rampant sexual violence; DNA evidence suggests that Genghis Khan may be “literally the father of Asia,” Montefiore writes. He insists, though, that “women among nomadic peoples enjoyed more freedom and authority than those in sedentary states,” and that the many wives, consorts, and concubines in a royal court could occasionally hold real power. The Tang-dynasty empress Wu worked her way up from concubine of the sixth rank through the roles of empress consort (wife), dowager (widow), and regent (mother), and finally became an empress in her own right. More than a millennium later, another low-ranking concubine who became de-facto ruler, Empress Dowager Cixi, contrasted herself with her peer Queen Victoria: “I don’t think her life was half so interesting and eventful as mine. . . . She had nothing to say about policy. Now look at me. I have 400 million dependent on my judgment.”