The law of the Eastern Catholic Churches in full union with Rome was in much the same state as that of the Latin or Western Church before 1917; much more diversity in legislation existed in the various Eastern Catholic Churches. Each had its own special law, in which custom still played an important part. In 1929 Pius XI informed the Eastern Churches of his intention to work out a Code for the whole of the Eastern Church. The publication of these Codes for the Eastern Churches regarding the law of persons was made between 1949 through 1958 but finalized nearly 30 years later.

Prior to 1917, what church was in a similar situation as the Eastern Catholic Churches as regards its legal system?