In this retirement he edified the Church by his penance and compunction, and laboured by his writings to enforce the observance of discipline and morality. He wrote a treatise to the bishop of Besançon, against the custom which the canons of that Church had, of saying the divine office sitting, a custom which has unfortunately, since his time, become general; but he saw the propriety of all sitting during the lessons. This saint wrote most severely on the obligations of religious, particularly against their rambling over the country, and going from monastery to monastery. He complained of certain evasions, by which many palliated real infractions of their vow of poverty. He justly observed, "We can never restore what is decayed of primitive discipline; and if we, by negligence, suffer any diminution in what remains established, future ages will never be able to repair such breaches. Let us not draw upon ourselves so base a reproach; but let us faithfully transmit to posterity the examples of virtue which we have received from our forefathers." The holy man was obliged to interrupt his solitude in obedience to the pope, who sent him in the capacity of legate, into France, in 1063, commanding the archbishops and others to receive him as himself. S. Peter there reconciled discords, settled the bounds of the jurisdiction of certain dioceses, and condemned and deposed in councils those who were convicted of simony. He notwithstanding, tempered his severity with mildness and indulgence towards penitents, where charity and prudence required such a condescension. Henry IV., king of Germany, in 1067, married Bertha, daughter of Otho, marquis of the Marches of Italy, but afterwards, in 1069, sought a divorce, and persuaded the Archbishop of Mentz to favour his design, by promising full payment of monies due to him if he complied, and threatening to fall on his territories with an armed band if he refused. For the purpose of sanctioning the divorce, the archbishop assembled a council at Mentz. Pope Alexander II. forbade him ever to consent to such an injustice, and chose Peter Damiani for his legate to preside in the synod. The venerable legate met the king and bishops at Frankfort, laid before them the orders and instructions of the pope, and in his name conjured the king to pay a due regard towards the law of God, the canons of the Church, and his own reputation, and seriously reflect on the public scandal of so pernicious an example. The noblemen likewise all rose up, and entreated their sovereign never to stain his honour by so foul an action. The king, unable to resist so cogent an authority, dropped his project of a divorce; but remaining the same man in his heart, continued to hate the queen more than ever.