Short answers, pulled from the story.
The Second Celtiberian War officially began in 154 BC with multiple tribes involved including Arevaci, Belli, and Titti groups. This conflict followed political tensions where Rome decided to withdraw all exemptions from Segeda despite their validity under current terms.
Quintus Fulvius Flaccus engaged the massive Celtiberian army near Talavera de la Reina during the siege of Aebura in 181 BC. Twenty-three thousand Celtiberians died during this engagement while four thousand seven hundred were captured by Roman forces.
Marcus Claudius Marcellus assumed command in 152 BC bringing eight thousand infantry and five hundred cavalry to avoid ambushes by moving cautiously. He seized Ocilis while granting pardon to its inhabitants and imposed thirty talents as fines along with hostage exchanges.
Numantines launched sorties killing four thousand Romans and three elephants during battles against Nobilitor's forces near Numantia. Heavy snowstorms and food shortages plagued his winter camp causing additional deaths among Roman troops.
The Numantine War lasted from 143 BC to 133 BC as the longest resistance against Roman expansion. Viriathus led Lusitanian rebels who incited Celtiberians to join their cause starting in 144 BC.