Origin of the gens
According to legend, the first of the Claudii was a
Sabine, by the name of
Attius Clausus, who came to Rome with his retainers in 504 BC, the sixth year of the
[i] At this time, the fledgling Republic was engaged in regular warfare with the Sabines, and Clausus is said to have been the leader of a faction seeking to end the conflict. When his efforts failed, he defected to the Romans, bringing with him no fewer than five hundred men able to bear arms, according to
Clausus, who exchanged his Sabine name for the
Latin Appius Claudius, was enrolled among the patricians, and given a seat in the
Senate, quickly becoming one of its most influential members.
[ii] His descendants were granted a burial site at the foot of the
Capitoline Hill, and his followers allotted land on the far side of the
Anio, where they formed the core of what became the "
Old Claudian" tribe.
Claudius is said to have referred to these traditions in a speech made before the
Roman Senate, in which he argued in favor of admitting
Gauls to that body. "My ancestors, the most ancient of whom was made at once a citizen and a noble of Rome, encourage me to govern by the same policy of transferring to this city all conspicuous merit, wherever found."
 By imperial times, the influence of the Claudii was so great that the poet
Virgil flattered them by a deliberate anachronism. In his
Aeneid, he makes Attius Clausus a contemporary of
Aeneas, to whose side he rallies with a host of quirites, or spearmen.
nomen Claudius, originally Clausus, is usually said to be derived from the Latin adjective claudus, meaning "lame". As a
cognomen, Claudus is occasionally found in other gentes. However, since there is no tradition that any of the early Claudii were lame, the nomen might refer to some ancestor of Attius Clausus. It could also have been metaphorical, or ironic, and the possibility remains that this derivation is erroneous. The metathesis of Clausus into Claudius, and its common by-form,
Clodius, involves the alternation of 'o' and 'au', which seems to have been common in words of Sabine origin. The alternation of 's' and 'd' occurs in words borrowed from Greek: Latin rosa from Greek rhodos; but in this instance clausus or *closus is a Sabine word becoming clod- in Latin. The name could have come from Greek settlers in Latium, but there is no evidence in favor of this hypothesis.