The coin shared today is a brockage of the Roman Republican denarius shown above. A brockage happens when a newly minted coin sticks to the top die, and then a second blank is put on the lower die and the two coins are struck together. I purchased the coin ~15 years ago - probably even earlier - my record keeping was non-existent before then. At the time it was one of the best preserved denarii in my collection. It is an interesting Roman Republic denarius - struck in Narbo, Gaul.
Here's a properly struck coin of the same type:
L. Cosconius M.f., 118 BC, AR serrate denarius, Narbo mint
Obv: Helmeted head of Roma right; X to left
Rev: Gallic warrior (Bituitus?), naked, driving a galloping biga right, hurling spear and holding a shield and carnyx
Size: 3.94g, 19mm
Ref: Crawford 282/2; Sydenham 521; Cosconia 1
The reverse references victories over the Gauls, and there are arguments that it could be a reference to Gallic King Bituitus, captured by the father of Cn Domitius Ahenobarbus - another subject of scholarly debate.
Crawford (RRC) describes the style as "markedly different" and "unparalleled" for both the erratic legends and the unusual administrative structure represented on the coin. It is signed by 2 senior moneyers (IIviri col. deduc.: the two highest officials responsible for leadership of the colony)
- L. Licinius Crassus (L LIC on reverse)
- Cn. Domitius Ahenobarbus (CN DOM on reverse)
and a junior moneyer
- L Cosconius (L COSCO M F on obverse)
4 other junior moneyers issued coins in this series with the the 2 senior officials.
Narbo Martius, modern day Narbonne, France, was established as a colony ~118BC as a strategic location on the road to Spain. The date, not without some past controversy, is based on this passage from Paterculus:
"A colony was established at Narbo Martius in Gaul about one hundred and forty-six years ago in the consulship of Porcius and Marcius." - Velleius Paterculus, Roman History, 1.15.5
Establishing a colony in Narbo was controversial in Rome as the senate worried about conflict with local populations and the scope of responsibility. The pro-colony argument was led by L. Licinius Crassus, who is described by Cicero a few decades later.
As he [Crassus] was then desirous to have the honour of settling the colony of Narbo (as he afterwards did) he thought it advisable to recommend himself, by undertaking the management of some popular cause. His oration, in support of the act which was proposed for that purpose, is still extant; and reveals a greater maturity of genius than might have been expected at that time of life. - Cicero, Brutus, a History of Famous Orators, 160
Here is another coin from this same issue in 118 BC (RRC 282/3).
Roman Republic, 118 BC, AR denarius serratus, Issued by: Cn. Domitius Ahenobarbus, L. Licinius Crassus, C. Malleolus, Mint: Narbo
Obv: C·MALLE·C·F X, helmeted head of Roma, right, wearing Attic helmet; around, inscription; behind, denominational mark. Border of dots.
Rev: L·LIC·CN·DOM, naked Gaulish warrior in biga, right, holding shield, carnyx and reins in left hand and hurling spear with right hand. Border of dots.
Mattingly, in his 1922 paper cited by Crawford (in RRC) shifts the dating from 92 BC and associates the coin with Narbo. Crawford didn't support other hypotheses from this paper e.g. the explanation for mark of value:
The 1877 article in Revue Archeologique (RA) that Crawford references is here.
"If we think of the importance that the complete defeat of the Allobroges and Arvernes had for the Romans, it is not surprising that they sought to perpetuate the memory by raising the Triumphal Arch of Orange and by striking coins featuring the captive king defeated by the Roman chiefs. Barely three years after the glorious feats of arms of which we have just spoken, the colony of Narbo Martius (Narbonne) was founded, which became the capital of the Roman province."
-J. De Witte, RA, 1887, 2, 137 (translation) De Witte didn't complete the connection: 92 av. J.C.
It seems that a colony was a cause of the "populares" for the potential to grant access to trade and farm land/land for grants.