Vadam is a Sangheili family. They live in Vadam, a relatively young yet powerful state in Yermo, Sanghelios. Their kaidon during the Human-Covenant War and the following years was Thel 'Vadam, later known as the Covenant's last Arbiter. The family's keep stands on Kolaar Mountain, Sanghelios and is located close to a harbor which brought wealth to the clan and the state. Vadam's land was well-developed and their serfs were strongly motivated and efficient, as their great ambitions were to gain distinction and receive a position inside the keep.
A story told by the future Arbiter about Vadam said that at one point the house was captured by an opposing clan and the Sangheili of Vadam were forced to rot within their own fortress's dungeons. Their kaidon, Ther 'Vadam, soon escaped, however, due to the fact that he was skinny enough to slide through his cell's bars. He escaped to the desert and quickly grew in power, and recruited bandits and outlaws to form an army. His newfound allies had statuses that were lower than Vadam's but they were willing to fight under Vadam's leadership.
Soon, Ther returned to what was rightfully his with his army, scaled the walls, and killed all his enemies before throwing their bodies in the river; legend has it that the river ran purple with Sangheili blood for days. After this was done, he killed those of Vadam who had been foolish enough not to commit honorable suicide within their dungeon cells.
This passage of Sangheili history demonstrates the harsh lifestyle and honor-based society of the Sangheili.
The day Thel 'Vadam assumed the rank of kaidon, in 2535, clan elder Koida 'Vadam sent assassins to kill him, a common practice among Sangheili if the kaidon's capability was in doubt; however, all of the three assassins were slain by Thel. Thel assembled the elders of his clan later the same day. Boldly announcing that the attempt on his life had failed, Thel promptly discovered and executed the culprit and exiled Koida's family line for his insolence.
Following the Great Schism and the end of the Human-Covenant War, Vadam became perhaps the most prominent state on Sanghelios as the home of the Arbiter, now a key mediator between humanity and the Sangheili.
- Thel 'Vadam - Kaidon
- Lak 'Vadamee - Elder
- Koida 'Vadam - Elder (deceased)
- Unnamed descendants
- Ther 'Vadam - Ancient kaidon