On 30 November 1894 , Pope Leo XIII publishes the Apostolic Letter Orientalium Dignitas ( On the Churches of the East ) safeguarding the importance and continuance of the Eastern traditions for the whole Church . On 30 November 1894 , Pope Leo XIII published the Apostolic Letter Orientalium Dignitas ( On the Churches of the East ) safeguarding the importance and continuance of the Eastern traditions for the whole Church .