of the apostles, which is known as apostolic succession. Since 1896, when Pope Leo XIII issued the bull Apostolicae curae, the Catholic Church has not recognised Anglican orders as valid, because of changes in the ordination rites that took place in the 16th century as well as divergence in the understanding of the theology of episcopacy and Eucharist. However, this view has since been complicated because Old Catholic bishops, whose orders are fully recognised as valid by Rome, have acted as co-consecrators in Anglican episcopal consecrations. According to the church historian Timothy Dufort, by 1969 all Church of England bishops had acquired Old Catholic lines of apostolic succession fully recognised by the Holy See. The Catholic Church does recognize, as valid but illicit, ordinations done by some independent Catholic groups such as the Old Catholic Church of the Utrecht Union and the Polish National Catholic Church, so long as those receiving the ordination are baptized males and a valid rite of episcopal consecration—expressing the proper functions and sacramental status of a bishop—is used. The Holy See also recognises as valid the ordinations of the Eastern Orthodox, Old Catholic, Oriental Orthodox and Assyrian Nestorian churches. Regarding the Churches of the East, the Second Vatican Council stated: Dress and vestments Latin Church The everyday dress of Latin Church bishops may consist of a black (or, in tropical countries, white) cassock with amaranth trim and purple fascia, along with a pectoral cross and episcopal ring. The 1969 Instruction on the dress of prelates stated that the dress for ordinary use may instead be a simple cassock without coloured trim. Since 1969, a black suit and clerical shirt, already customary in English-speaking countries, has become very common also in countries where previously it was unknown. A Latin Church bishop's choir dress, which is worn when attending but not celebrating liturgical functions, consists of the purple cassock with amaranth trim, rochet, purple zuchetto, purple biretta with a tuft, and pectoral cross. The cappa magna may be worn, but only within the bishop's own diocese and on especially solemn occasions. The mitre, zuchetto, and stole are generally worn by bishops when presiding over liturgical functions. For liturgical functions other than the Mass the bishop typically wears the cope. Within his own diocese and when celebrating solemnly elsewhere with the consent of the local ordinary, he also uses the crosier. When celebrating Mass, a bishop, like a