Grounders

The Grounders, also called Outsiders and Savages by the Mountain Men, is a term used to describe a person who was born on Earth's ground rather than in space or within Mount Weather.

The Grounders initially had a passive-aggressive relationship with the Sky People, as well as a long history of fighting the Reapers and Mountain Men. The Azgeda Grounders (and Diana Sydney's people) were the main antagonists of the first season.

The Grounders alive today are descendants of humans who survived the Nuclear Apocalypse in 2052. Since then, 12 Grounder Clans were established in the former territory of the Northeastern United States. After many years of in-fighting, the 12 Clans were united by Commander Lexa under her Coalition.

When the Delinquents first landed in their territory, Lexa believes they have came to reclaim "the one they have lost", meaning Kent Griffin. Lexa sends Kent and Lincoln to gather information on the invaders and identify their leader. After being brought to Polis, Bellamy Blake negotiates and makes a deal that would result in the killing of the Ark and freedom for the 100. Clarke Griffin finds out about this and decides she needs to speak with Lexa. Clarke and her estranged brother, Kent who's also the Earth-brother of the Commander, travel to Polis where Clarke explains that the Ark has more to offer the Coalition than if they were dead. She strikes a deal, and potential alliance, which consisted of targeting Nia in revenge for Costia. From then on, the Sky People were aligned with the Coalition. After the rest of the Ark lands, the Arkers are given clearance by Lexa to live on her lands. The alliance was jeopardized however, when Lexa betrayed the Sky People by making a deal with the Mountain Men to ensure the Grounders' safety.

History
The Grounders are the Earth-born descendants of radiation-tolerant humans and doomsday preppers who survived the Nuclear Apocalypse that took place in 2052. Not much is known about their history on Earth after that, though at some point, twelve Grounder Clans were established and, after many years of fighting, were eventually united under the Coalition.

Although their ancestors were Nightbloods, very few Grounders have inherited this trait. According to Dante Wallace of the Mountain Men, the DNA of the offspring of the Grounders who survived on Earth outside Mount Weather evolved and adapted, making them immune to the radiation that lingers on Earth, much like the people from the Ark (who were immune through exposure to solar radiation in space).

Population
It is unknown how many Grounders are in the area. There are 12 Clans as well as an unknown number of nomadic Grounders. Altogether, they have the highest population count by far of the residents in the Tondc-Mount Weather area, with a combined army numbering in the thousands (Azgeda alone had a total of over a thousand warriors).

Beyond the Northeastern United States region, it is extremely likely that there are more Grounders.

In "The Queen and the Heda", Nia reveals to Diana Sydney that when the Exodus ship landed, an Azgeda village was decimated and all of the residents were killed. In "Ring-a-Ring O' Grounders", a combined total of 537 Polis Army and Azgeda warriors are killed in result of the conflict. In "Jus Drein Jus Daun (Part I)", it is revealed that Cage Wallace sent a missile to a Tondc village, killing 250 Grounders and Sky People.

Languages
Trigedasleng is the native language of the Grounders, spoken by most if not all Grounder clans. Grounders from various clans including Trikru, Azgeda, Floukru, Trishanakru, Louwoda Kliron and Sangedakru, as well as the Nomadic Grounders, have all been shown to speak Trigedasleng, though different dialects among the clans do exist.

Typically, only the Warriors speak English (Gonasleng), which makes them bilingual. But many Grounders who aren't warriors have been seen speaking English.

Faith
The Grounder faith centers on the Flame. The highest-ranking Grounder is traditionally the Commander a.k.a. the bearer of the Flame. Even when there is no Commander, many Grounders still remain loyal to the Flame.

Flamekeepers
The Flamekeepers are a group of Grounders who act as spiritual members, teachers and guides to the Commander. They are tasked with protecting the Flame.

Nightbloods
Nightbloods, also known as Natblida, are Grounders with black blood. When a Nightblood child is discovered, they are supposed to be sent to Polis to begin training for the Conclave in hopes of one day ascending to become the next Commander.

Capital Punishment
Capital punishment in the form of Death by a Thousand Cuts occurs when every single member of the clan takes a turn cutting the convicted before feeding them to the bugs. For more egregious crimes, they start with fire and take the hands, tongue, and eyes. Everyone gets a turn with the knife before the Commander ends it with the sword if the person is still alive by then.

The tongue is cut out when a person slanders or speaks blasphemy about the Commander.

Single Combat
When a Grounder leader's strength is in doubt, they can be challenged to a single combat duel, also known as solo gonplei.

Technology
The Grounders live in the ruins of a great civilization, but they have fallen far from the heights just before the Nuclear Apocalypse. Grounders live in scattered villages, farming, hunting, and gathering. They use muscle-powered weapons like bows, spears, and swords ground from scrap metal; they ride horses; and their healers use herbs and poultices rather than modern medical techniques, but their weapons, transportation, and healing are all remarkably effective.

Polis has a library filled to the brim with books that survived the fires of the Nuclear Apocalypse. Kent Griffin has said several times that he's visited the Polis Library many times. Kent has read a vast variety of books present in the library, including but not limited to: Egyptian mythology (he knows about the Egyptian deities), Greek mythology (he once checked it out but was not too interested), Pharmacology and Modern Medicine (he knows what an intravenous drip feed, an IV, is), and Engineering and Mechanics (he was able to understand and assist Raven with the dropship ignition).

Names
Grounder names for places and people are often derived from the names of earlier locations or landmarks that have had their names weathered away in parts from associated signage. For example, Indra is the leader of TonDC, a derivation of Washington, DC, and Polis, the capital city of the Coalition, is named after the space station Polaris. Lincoln is named after the presidential memorial, while Lexa and Ontari are named after the city of Alexandria and the province of Ontario, respectively.

Since the Grounders do not use last names, their clan name is used instead. Lexa's full name, for example, can be considered to be Leksa kom Trikru ("Lexa of the Woods Clan" in Trigedasleng). Clan names also appear to be geographically derived.