Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
This and other misfortunes-- such as the destruction of a corps of Roman cavalry despatched to call forth the contingents--imparted to the affairs of the Romans in the Hither province so unfavourable an aspect that the fortress of Ocilis, where the Romans had their chest and their stores, passed over to the enemy, and the Arevacae were in a position to think, although without success, of dictating peace to the Romans.
These disadvantages, however, were in some measure counterbalanced by the successes which Mummius achieved in the southern province. Weakened though his army was by the disaster which it had suffered, he yet succeeded with it in defeating the Lusitanians who had imprudently dispersed themselves on the right bank of the Tagus; and passing over to the left bank, where the Lusitanians had overrun the whole Roman territory, and had even made a foray into Africa, he cleared the southern province of the enemy.
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Reference address : https://www.ellopos.net/elpenor/rome/4-01-gracchi.asp?pg=7