In the later years of this long and bloody controversy, it is evident that the political element greatly complicated the religious ground of quarrel—that pope and emperor without made use of burgher and noble within, and the latter took sides, as respects simony and sacerdotal marriage, to further the ends of individual ambition. Still, the disputed points of discipline were the ostensible causes of the struggle, whatever might be the private aims of civic factions, or of imperial and papal rivals; and these points gave a keener purpose to the strife, and furnished an inexhaustible supply of recruits to each contending faction. Thus, about the year 1070, a conference took place at Milan between priests deputed by both sides, in which the question of marriage was argued as earnestly as though it were the source of all the intestine troubles.[524] So when, in 1073, Gregory, shortly after his accession, addressed letters to Erlembaldo urging him to persevere in the good work, and to the Lombard bishops commanding them to assist him, the object of his labors is assumed to be the extirpation of simony and the restoration of the clergy to the purity becoming their sacred office.[525] And when, in 1076, the schismatic bishops, under the lead of Tedaldo of Milan, met in council at Pavia to renounce all obedience to Gregory, one of the articles of accusation brought against him was that he separated husbands and wives, and preferred licentiousness to marriage, thus giving, in their grounds of complaint against him, especial prominence to his zeal for the introduction of celibacy.[526]