Territorial abbey

A territorial abbey (or territorial abbacy) is a particular church of the Catholic Church comprising defined territory which is not part of a diocese but surrounds an abbey or monastery whose abbot or superior functions as ordinary for all Catholics and parishes in the territory. Such an abbot is called a territorial abbot or abbot nullius diœceseos (abbreviated abbot nullius and Latin for "abbot of no diocese"). A territorial abbot thus differs from an ordinary abbot, who exercises authority only within the monastery's walls or to monks or canons who have taken their vows there. A territorial abbot is equivalent to a diocesan bishop in Catholic canon law.

The coat of arms of a territorial abbot are distinguished by a green galero with twelve tassels and a gold crozier with a veil attached.

While most belong to the Latin Church, and usually to the Benedictine or Cistercian Orders, there are Eastern Catholic territorial abbeys — most notably the Italo-Greek Abbey of Grottaferrata.