Just off the sacristy of the Lateran Archbasilica in Rome you can see this nice bust of Pope Pius XII, of blessed memory. The canons placed this here in honor of their Papa Romano who saved their city during the last great war. In that same property, living with the canons, were hid many notables during WWII, including the first president of post-war Italy, Alcide De Gasperri.
The great XXth century magna carta on the liturgy was the 1947 encyclical letter called Mediator Dei. If you have an interest in liturgy, then please see here: