Senate of the Roman Kingdom

[3] 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.

[2] Each clan was an aggregation of families under a common living male patriarch, called a pater (the Latin word for "father").

According to Abbott, however, what likely happened was a gradual aggregation of patres over time, as more clans achieved high status.

[5] The early senate derived its ultimate sovereignty from the fact that it was composed of the patriarchal heads of the leading families.

[7] One hundred more men were added to the Senate by Rome's fifth king, Lucius Tarquinius Priscus, from amongst the minor leading families.

[8] The senate of the Roman Kingdom could only be convened by the king, and usually met in either a templum, or in some other location that had been consecrated by a religious official (an augur).

This tradition was maintained throughout the life of the Roman Republic, although in practice, the republican magistrates rarely acted against the wishes of the senate.

[9] The patres that filled the ranks of the early senate held a position of absolute dominance over their respective families.

During the first interregnum after the death of Romulus, the senate, comprised at that time of 100 men, arranged itself into ten decuries, and each decurio governed Rome for five days as interrex.

The decurios continued to rotate the government amongst themselves for a year until the senate elected Numa Pompilius as king.