Romulus and Remus were discovered by a she wolf after being left for dead by the Tiber. Most likely they were actually found by a farmer and his less than faithfull wife.
The twins eventually decided to build a city on the Tiber where they were found all those years ago. In order to decide which hill to place the city they used birds as the deciding factor. Remus said he had more and Romulus said he had more so Remus jumped the wall that Romulus was building. Romulus did not like this so he killed him with a shovel. Rome was then started where Romulus wanted it with Romulus being the 1st King.
I like not getting stuck by lightning bolts!
Numa Pompilius, the 2nd King, made many advancements when it came to Roman religion. He created the Flamen and in general made Rome more religious.
The next King, Tullus Hostilius, was a very warlike King. He disregarded the Gods and did not follow Numa's teachings. He is one reason for Rome's bellicose nature. After a plague hit, he prayed to Jupiter but he struck him with a bolt of lightning.
Tarquinius Superbus, the last king, was exiled from Rome because his son raped Lucretia. After this Rome became a Republic. However, Superbus was not done with Rome yet...
When Superbus returned, he returned with an army with the intention a taking Rome for his own. Although the battle did not take place over a chasm, it did take place on a bridge over the Tiber. A Roman soldier named Cocles defended the bridge until the other Roman soldiers finished cutting it down into the Tiber.