However, the church would start worrying soon about the proliferation of liturgies. From the mixture of the galican liturgy with the antique Roman one would result, traditionally under pope Gregory I (540–604), the modern Roman liturgy, also known as Gregorian liturgy, comprising the Gregorian chant. This would become the official liturgy of the Catholic Church and substituted gradually the local ones. In the Iberian Peninsula, the Council of Burgos decreed the substitution of the Hispanic rite by the modern Roman one in 1080. This measure was eased by the fact that, during the Reconquista, most part of the bishops were French (Gérard, Maurice Bourdin, Jean Péculier, Bernard, Hughes).