(Spoiler Alert! This article contains information about the last episode of "Game of Thrones.")

After eight seasons, the epic "Game of Thrones" TV series finally resolved the question of who will reign — with an unexpected twist. Bran "the Broken" Stark rolled into position as the new monarch of the Six Kingdoms, but no longer will a king or queen's rule be automatically inherited by their children.

And that's a good thing: Much of the political upheaval throughout the HBO series stemmed from uncertainty about the lawful heir to the throne. While it's anyone's guess what lies ahead for Westeros under its new system, we know from European history that hereditary succession can cause disruptions that reverberate to this day.

In fact, researchers recently found that when male heirs for medieval European monarchies were in short supply, the resulting social discord hampered economic growth for generations. As a result, countries in regions that lacked male heirs "are today poorer than other regions," scientists reported online March 11 in the journal Comparative Political Studies. [5 Real-Life Inspirations for 'Game of Thrones' Characters]

During the Middle Ages in Europe, around the years 1000 to 1500, direct male descendants were the most desirable heirs for a throne or noble title. Women and distant male descendants could also fill those roles; however, these were more likely to spark dissent and violence among rival groups of supporters, and the fighting could undermine future economic growth, the researchers wrote.

In regions where monarchs were lucky enough to have male heirs, allowing for uncontested leadership transitions, "rulers were able to build the state institutions necessary to support economic development," the scientists wrote.

"In areas burdened by a greater potential for political instability, the path to economic prosperity was much more arduous," the researchers said.

What about illegitimate male heirs? In "Game of Thrones," King Joffrey Baratheon called for the murder of all his father's bastards so that none could challenge the new king's claim to the throne. But in the study, the researchers determined that medieval taboos against succession by illegitimate sons were so strong that the number of bastard "heirs" didn't have much of an effect on medieval politics.

Over the centuries, other factors across Europe also shaped social and economic fortunes, the scientist reported. But the fingerprints of medieval hierarchies left a powerful imprint; France and Naples, for example, had consistent male lineages during the Middle Ages, and even today, those areas tend to be better off economically than some of their neighbors, according to the study.

"The emergence of the first modern states in this period was so important, and the states themselves so fragile, that even small disruptions could have long-term consequences," the researchers wrote.

Fans of "Game of Thrones" will have to imagine for themselves whether Westeros' new approach to leadership — where new rulers are chosen by a noble council, rather than preordained by heredity — will prove successful. Judging from the council's uproarious reaction to Sam Tarly's proposal that they empower the common people to choose a leader, the Six Kingdoms clearly isn't ready to embrace democracy just yet.

Originally published on Live Science.