Three Oecumenical Conferences have been held - two at City Road, London, in and 1901, and one at Washington in 1891.
Articles 6 and 7 forbade access of any Italian official or agent to the above-mentioned palaces or to any eventual conclave or oecumenical council without special authorization from the pope, conclave Or council.
The first trace of system is in the limited right of appeal given by the first oecumenical council of Nicaea and its provision that episcopal sentences or those of provincial synods on appeal were to be recognized throughout the world.
The third and fourth oecumenical synods (Ephesus, 43 1; Chalcedon, 451) were primarily tribunals for the trials of Nestorius and Dioscorus; it was secondarily that they became organs of the universal episcopate for the definition of the faith, or legislative assemblies for the enactment of canons.
No oecumenical synod has tried a patriarch of Old Rome while yet in the flesh.