Every self-respecting rapper, so I hear, has his posse of friends or hangers on. Taylor Swift too. Central Eurasian bigshots took the concept further:
In the early form of the Central Eurasian Culture Complex, the highly trained warrior members of a lord’s comitatus— a guard corps loyal not to the government but to the lord personally— took an oath to defend him to the death. The core members of the comitatus, his sworn friends, committed suicide, or were ritually executed, in order to be buried with him if he happened to predecease them. The peripheral cultures’ historical sources explicitly say so, time and again, as Ibn Faḍlân remarks about the Vikings on the Volga, who were known as Rus:
One of the customs of the king of the Rus is that with him in his palace he has four hundred men from among his most valiant and trusted men. They die when he dies and are killed for his sake.
Beckwith, Christopher I.. Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present (p. 16). Princeton University Press. Kindle Edition.
* The term has a somewhat different meaning in English Common Law.