Romulus and Remus were born from Mars, the god of war and Rhea Silvia, the daughter of King Numitor. After Rhea's uncle, take over the throne, he planned to thrown the twin into the River Tiber as he didn't want anyone to take his throne.
Luckily, they got rescued by a wolf who take care of them to become healthy children. Then, they were founded by the Shepherd Faustulus who didn't have children, so he took them home.
After they found out about themselves from their grandfather, Numitor, they planned to build an army and revenge for their grandfather and mother lost. They killed Amulius and put their grandfather back on the throne.
God of Quirinus
Then, they built their own city as they couldn't make an agreement on where to build. Remus was killed by Remulus as he made fun of Remulus' city wall, and then he became the first king of Rome in 753 B.C.E.
To populated his city, he stole women from the Sabine tribe to provide wives for his villager which include slaves and criminal. And that consequences to war, but eventually reached an agreement where Sabrines became part of Rome under the leadership of Remulus.
As Remulus was believed to do lots of good things during his life, he was carried by his father, Mars and represent as the god of Quirinus.