Was the gladiator fighting always part of the roman culture and law?

Answer 1

No it was not. The Romans did not invent the gladiatorial combats. They originated from outside Rome. Nicolaus of Damascus believed them to be of Etruscan origin. Livy thought that that they were first held in 310 BC by the Campanians (a people who lived south of Rome, near Naples) to celebrate a victory in a war. Both men were ancient historians. Recent evidence suggests that the combats either originated or were borrowed from Campania.

Rome was founded in 753 BC. Livy said that the earliest Roman gladiator games occurred in 264 BC. Decimus Iunius Brutus Scaeva had three gladiator pairs fight to the death to honour his dead father, Brutus Pera. Originally the gladiatorial contests were part of funerary rituals, the munus (plural: munera), which was a commemorative duty owed the manes (deities which represented the souls of deceased loved ones) of a dead ancestor by his (rich) descendants. Later, staring from Julius Caesar (in the 40s BC), they developed into games for public entertainment.