The Senate of the Roman Kingdom was a political institution in the ancient Roman Kingdom. The word senate derives from the Latin word senex, which means "old man". Therefore, senate literally means "board of old men" and translates as "Council of Elders". The prehistoric Indo-Europeans who settled Rome in the centuries before the legendary founding of Rome in 753 BC were structured into tribal communities. These tribal communities often included an aristocratic board of tribal elders, who were vested with supreme authority over their tribe. The early tribes that had settled along the banks of the Tiber eventually aggregated into a loose confederation, and later formed an alliance for protection against invaders.