After Romulus' death, there was no clear successor; Romulus had not left one successor! Therefore, the Senators decided to reign by themselves for a time. The Senators were a group of 100 men. They were chosen by Romulus himself, and dealt with the law, The Senate formed 10 groups of 10 people each (for 10*10 = 100), and each group would reign for a time. During the groups turn, each person in the group would take turns reigning. This worked for a few years but later the citizens of Rome wanted a real King. They would vote for other people that wanted to be King, then the Senate would say, " YES," or, "NO." The people all voted for a Sabine named Numa Pompilius. Numa Pompilius was known for his Justice and Wisdom. The Senators wanted to reign by themselves, but they could find no reason to say, "NO" to Numa's being King. Hence, Numa was selected as the King.
During King Numa's peaceful reign, he built a famous temple to a Roman god named Janus. Janus was the god of boundaries, The building of the temple of Janus is a sign of his keeping peace. The important part of the building was not the inside, where the statues and other things were, but the important part was the temple doors.. Usually the doors are open in war, so as to increase the boundaries, but in peace, the doors were closed. In King Numa's reign, the doors were almost always closed, for his kingdom was almost always at peace.
Numa Pompilius was remembered for many things. King Numa developed the worship in the gods of Rome. He also reorganized the calendar of Rome. Moreover, Numa Pompilius made the position called the Pontifex Maximus. The Pontifex Maximus is otherwise known as the High Priest. This office was the most important one.
Numa Pompilius reigned from 715-673 BC. He was very different from Romulus. King Numa was peaceful, while the latter was warlike. They made a great mix; King Romulus increased the
boundaries, while Numa Pompilius developed it.