Due to the region's history the Ukrainian Greek Catholic Church attained a strong Ukrainian national character, and the Polish authorities sought to weaken it in various ways. In 1924, following a visit with the Ukrainian Catholic believers in North America and western Europe, the head of the UGCC was initially denied reentry to Lviv for a considerable amount of time. Polish priests led by their bishops began to undertake missionary work among Eastern Rite faithful, and the administrative restrictions were placed on the Ukrainian Greek Catholic Church.