Titus Tatius

According to the Roman foundation myth, Titus Tatius was the king of the Sabines from Cures and joint-ruler of Rome for several years.

During the reign of Romulus, the first king of Rome, Tatius declared war on Rome in response to the incident known as the rape of the Sabine women. After he captured the stronghold atop Capitoline Hill with the treachery of Tarpeia, the Sabines and Romans fought an epic battle that concluded when the abducted Sabine women intervened to convince the two sides to reconcile and end the war. The two kingdoms were joined and the two kings ruled jointly until Tatius' murder five years later. The joint kingdom was still called Rome and the citizens of the city were still called Romans, but as a community, they were to be called Quirites. The Sabines were integrated into the existing tribes and curies. Tatius is not counted as one of the traditional "Seven Kings of Rome".

He had one daughter Tatia, who married Numa Pompilius (Romulus's successor), and one son, who was the ancestor of the noble family of Tatii.

Dionysius of Halicarnassus reports that after a year of preparation, Rome and the Sabines engaged in several skirmishes and minor engagements, before fighting two major battles. two days after the first, the second and final battle between them was fought in between the two Roman hills they were occupying. It was an epic contest, featuring multiple reversals wherein both armies had and then lost the upper hand. At the end of the day, the Sabines retreated to the citadel and the Romans didn't pursue them.

Before combat could be resumed, the Sabine women, some in funerary attire, some carrying their children with them, convinced Tatius and Romulus to end the fighting. After a ceasefire, the nations signed a treaty creating a single kingdom under the joint rule of both kings. They reigned together until the death of Tatius.

...
Wikipedia