Roman authors for unknown reasons wrote that the Belli were of mixed Illyrian and Celtic origin and probably related with the Bellovaci, who were said to have migrated to the Iberian Peninsula around the 4th Century BC and part of the Celtiberians. There is an overwhelming amount of evidence that the ancestors of the Celtiberian groups were installed in the Meseta area of the peninsula from at least 1000 BC and probably much earlier.
Location
The Belli inhabited the middleJiloca and Huervariver valleys in Zaragoza province with their territories stretching up to the Guadalope and upper Turia valleys, close to their neighbours and clients, the Titii. Their early capital was Segeda, subsequently transferred to nearby Durón de Belmonte and later offset by Bilbilis. Other Belli urban centers included Nertobriga, Contrebia Belaisca, Beligiom, Lesera and Belgeda. It is plausible that by the 2nd Century BC they exerted some form of control over the strategic frontier towns of Belia, Osicerda, Damania and Orosis, facing the IberianLobetani and Edetani peoples of the modern Valenciacoastal region.
Culture
The most culturally advanced of the peoples of southern Celtiberia, the Belli were the first Celtiberian tribe to adopt coinage in the aftermath of the 2nd Punic War and to post laws in written form on bronze tablets, using a modified Northeastern Iberian script for their own language. In this script and language they inscribed the characteristic Celtiberian 'hospitality tokens' which are small bronze objects, in two halves, each half being retained by people who stood in hospitality relationship to one another. These would act as a sort of identity card, and were probably used as safe-conducts or other warranties. The two halves have been found in places several hundreds of kilometres apart, which implies that the various Celtic groups maintained a system of communications throughout at least central Spain. The most complete Celtiberian text we have on the bronze 'hospitality tokens' that acted as a sort of identity card is from the Belli and reads lubos alisokum aualoske kontebias belaiskas meaning 'Lubos of the Aliso family, son of Aualos, from Contrebia Belaisca' showing the self-description of this man, by paternity, extended family and territory which is characteristically Celtic.
Defeated in 143 BC by Proconsul Quintus Caecilius Metellus Macedonicus, and faced with the fall of Numantia in 133 BC and the subsequent collapse of the Celtiberian confederacy, the Belli territory was incorporated into Hispania Citerior province though little is known of their history afterwards. The Belli appear to have remained independent until the Sertorian Wars of the early 1st Century BC, when they were gradually pushed back from the upper Jiloca by the Edetani who seized Beligiom, Belgeda, Damania and Orosis, therefore losing all the lands east of the Huerva River. Around 72 BC they and their Titii allies merged with the pro-Roman Uraci, Cratistii and Olcades tribes to form the Late Celtiberian people of romanized southern Celtiberia.