The paper aims to provide some elements related to the theme of the relationship between the Holy See and the Liturgical Movement in the years of Pius XII’s pontificate, presenting in particular some documents drafted by Cardinal Raffaello Carlo Rossi in the 1940s. His contribution was indeed essential for the acceptance of some of the main theological instances of the Movement in Mediator Dei. A transcription of the main vota found in the archives of the Holy See is offered in the appendix.