The principal patron of the Archdiocese is the Blessed Virgin Mary Mother of Mercy.
Nowadays the principal patron is the Blessed Virgin Mary Mother of Mercy (NMP Łaskawa).
The patron's day is celebrated on 1 April, the day when King of Poland Jan II Kazimierz Waza took an oath at the Lwów Cathedral in 1655, during "The Deluge," took vows of loyalty to God and declared the Mother of God to be the Queen of Poland.
An attempt to liquidate the Catholic Church in Ukraine was made with the start of World War II in 1939 and partition of Poland between Nazi Germany and Soviet Union.
After World War II and until fall of the Soviet Union, the Archdiocese of Lwów was centered in Lubaczów.