After receiving his education at Prague he joined the Knights of the Cross with the Red Star, an ecclesiastical order established in Bohemia in the thirteenth century.
They refused to permit their candidates for the priesthood to undergo examination on Catholic theology or to give proof of their orthodoxy, and complained to the emperor that the archbishop was infringing upon their rights.
In order to publish and put into execution the decrees of the Council of Trent, the archbishop intended to convene a provincial synod at Prague; but Maximilian, fearing to offend the Bohemian nobility of whom the majority were Protestants, withheld his consent.
The Utraquists no longer heeded the archbishop's commands, continued to administer the Holy Eucharist to infants, disregarded many decrees of the Council of Trent, neglected sacramental confession—in a word, were steering straight towards Protestantism.
After the death of Brus, the Catholics of Bohemia continued on their downward course until the victory of Ferdinand II over the Winter King Frederick V at the Battle of the White Mountain near Prague (8 November 1620).