The word Senate has its origin in the Latin "Senatus" which in turn comes from "Senex" whose meaning is "Senile or Old." The Senates were originally established in Rome, where Romulus, their first King created them, they were organizations composed of one hundred people, which were entirely Pater Familia (fathers of the family), since they were the men belonging to the most important social sector. Subjects belonging to the Senate are called or given the title of Senators.
The oldest Senators were the most appreciated politically speaking, if the case in which the King died was presented, they would temporarily replace it, starting with the oldest and their period of time in royal power was five days each., until a new King was crowned.
In the development of Rome, that is, when the Roman Republic was created there were many changes in the number of senators belonging to the Senate, there came a time when there were a thousand men belonging to it, with the arrival of the Emperor Augustus they were reduced to six hundred. Subsequently, the decisions of the senators obtained a hierarchical rank of law, however, as time passed, they lost such value.
Currently the body that assembles the Legislative Power of a nation is called Senate. Its main function is to approve or disapprove the bills that want to be applied in a democratic state. In some countries, senators are elected by popular will undergoing electoral suffrage and in others they are appointed by the chief executive or national executive.
