Titus Livius (Livy), The History of Rome, Book 1
Rev. Canon Roberts, Ed.

52. After¹ the Latins had reassembled in council and had been commended by Tarquin for having inflicted on Turnus a punishment befitting his revolutionary and murderous designs, Tarquin addressed them as follows: [2] It was in his power to exercise a long-established right, since, as all the Latins traced their origin to Alba, they were included in the treaty made by Tullus under which the whole of the Alban State with its colonies passed under the suzerainty of Rome. [3] He thought, however, that it would be more advantageous for all parties if that treaty were renewed, so that the Latins could enjoy a share in the prosperity of the Roman people, instead of always looking out for, or actually suffering, the demolition of their towns and the devastation of their fields, as happened in the reign of Ancus and afterwards whilst his own father was on the throne. [4] The Latins were persuaded without much difficulty, although by that treaty Rome was the predominant State, for they saw that the heads of the Latin League were giving their adhesion to the king, and Turnus afforded a present example of the danger incurred by any one who opposed the king's wishes. [5] So the treaty was renewed, and orders were issued for the ‘juniors’² amongst the Latins to muster under arms , in accordance with the treaty, on a given day, at the Grove of Ferentina. [6] In compliance with the order contingents assembled from all the thirty towns, and with a view to depriving them of their own general or a separate command, or distinctive standards, he formed one Latin and one Roman century into a maniple, thereby making one unit out of the two, whilst he doubled the strength of the maniples, and placed a centurion over each half.