Developing an interest in Eastern liturgical traditions and, with his background in Russian, Taft undertook studies at the Pontifical Oriental Institute of Rome in 1970.

He completed his doctoral thesis under Jesuit professor Juan Mateos on the Great Entrance of the Divine Liturgy in 1975.

Consultor of several ecclesiastical dicasteries and the Vatican Congregation for the Oriental Churches, he was founder of the Societas Orientalium Liturgiarum.

Working with Taft's analysis of the situation, the Pontifical Council for Promoting Christian Unity issued a decree in 2001 which now allows members of both churches to receive communion from each other's clergy in case of emergency.

[6] Taft died on November 2, 2018,[9] after which numerous scholarly and ecclesiastical communities both Catholic and Orthodox made official statements in mourning and organized academic conferences and publications to commemorate his passing.

[citation needed] Taft's numerous publications, particularly on the history of Byzantine Liturgy, can be found in a variety of specialized journals.