And now Servius began to strengthen his power, not more by public than by private measures; and, that the children of Tarquin might not entertain the same feelings toward himself as the children of Ancus had entertained toward Tarquin, he united his two daughters in marriage to the young princes, the Tarquinii, Lucius and Arruns. He did not, however, break through the inevitable decrees of fate by human counsels, so as to prevent jealousy of the sovereign power creating general animosity and treachery even among the members of his own family. Very opportunely for the immediate preservation of tranquility, a war was undertaken against the Veientes (for the truce had now expired) and the other Etruscans. In that war, both the valour and good fortune of Tullius were conspicuous, and he returned to Rome, after routing a large army of the enemy, undisputed king, whether he tested the dispositions of the fathers or the people. He then set about a work of peace of the utmost importance: that, as Numa had been the author of religious institutions, so posterity might celebrate Servius as the founder of all distinction in the state and of the several orders by which any difference is perceptible between the degrees of rank and fortune. For he instituted the census,[39] a most salutary measure for an empire destined to become so great, according to which the services of war and peace were to be performed, not by every man, as formerly, but in proportion to his amount of property. Then he divided the classes and centuries according to the census, and introduced the following arrangement, eminently adapted either for peace or war.