So-called Altar of Domitius Ahenobarbus (1st century BC): from Rome. now in the Louvre Museum, Paris

Victory over the Cimbri (100 BC)

Fiona Tweedie (referenced below, at pp. 128-9)

1. “Rome and Italy defeated the marauding bands of the Cimbri and their allies in a desperate campaign that gave real meaning to the alliances that bound the inhabitants of the peninsula. ... This victory was presented as the salvation of tota Italia and feelings of unity among the participants in the campaign were at a high point.  The role of the saviour of Italia, C. Marius, is critical to what followed.  Marius recognised the importance of the allies to Rome’s success and employed a policy of liberality with the citizenship, demonstrated by such gestures as his enfranchisement of a troop of cavalry from Camerinum and the citizenship provisions in the colonial laws that L. Appuleius Saturninus passed for him.”
   

Census of 97 BC

Fiona Tweedie (referenced below, at p. 129) pointed out that at least one of the censors of 97 BC, L. Valerius Flaccus (cos 100 BC) was an ally of Marius, while the other M. Antonius, does not appear to have been hostile to him.  She also observed (at p. 128) that:

1. “The euphoric atmosphere that followed [the victory of Rome and Italy against a common enemy, the Cimbri in 100 BC]  surely influenced the census [three years later].”
   

Lex Licinia Mucia (95 BC)

This law was promulgated by the consuls of 95 BC: L. Licinius Crassus and Q. Mucius Scaevola (the pontefex maximus).   Fiona Tweedie (referenced below, at p. 135) deduced that it:

1. “... probably required that anyone who had been registered [as a citizen of] an allied community at a certain date should reregister in that community unless he could demonstrate why his claim to Roman citizenship should be honoured.”
   

She translated (at p. 123) a relevant fragment of the ‘Pro Cornelio’, a speech that Cicero delivered in 65 BC, which is preserved in a commentary on it by Asconius (who was writing about a century later): Cicero had apparently noted that:

1. “... everyone is agreed that the Licinian-Mucian law concerning the return to one’s own citizenship, [despite the fact that it had been promulgated by]  two consuls who were the wisest of all, was not only useless (inutilis), but also very destructive of the public good (perniciosam rei publicae).’”
   

Asconius himself recorded that this law had been needed because:

1. “... the Italian peoples were gripped by a great desire for the Roman citizenship and because ... [many]  them were [illegitimately] presenting themselves as Roman citizens ... . The feelings of the leaders (principes) of the Italic peoples were so alienated by this law that it became the main reason for the bellum Italicum, which broke out three years later”.
   

In his speech of 56 BC in defence of L. Cornelius Balbus, whose claim of Roman citizenship was challenged, Cicero observed that:

1. “...  a very severe investigation (acerrima quaestio) of the citizenship was conducted under the Licinian Mucian law”, (‘Pro Balbus’, 48-9, based on the translation by  Fiona Tweedie (referenced below, 2012, at p. 131).
   

Tweedie argued (at p. 135) that:

1. “Cicero’s description of an acerrima quaestio under the law suggests that ... a larger number of trials occurred than is commonly imagined.  If significant numbers of allies were condemned, we can begin to understand the terrible impact that the law had on relations between Rome and the allied communities, especially if the principes of the allied communities were numbered among the victims.”
   

Census of 92 BC

Fiona Tweedie (referenced below, at pp. 136-7) argued that:

1. “An even stronger link between the [lex Licinia Mucia]  of 95 BC and the crisis of 91 BC can however be found: in 92 BC, a new census was due to be held, and new censors:
   

2. ✴L. Licinius Crassus, consul in 95 BC and one of the authors of the law, and
   

3. ✴Cn. Domitius Ahenobarbus, consul in 96 BC and pontifex maximus,
   

4. were elected. ... [This] was the moment at which compliance with the Lex Licinia Mucia [was about to] be tested.”