Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Council in Trullo; Often Called The Quinisext Council.: Canon XXXVI

Canon XXXVI.

Renewing the enactments by the 150 Fathers assembled at the God-protected and imperial city, and those of the 630 who met at Chalcedon; we decree that the see of Constantinople shall have equal privileges with the see of Old Rome, and shall be highly regarded in ecclesiastical matters as that is, and shall be second after it.  After Constantinople shall be ranked the See of Alexandria, then that of Antioch, and afterwards the See of Jerusalem.

Notes.

Ancient Epitome of Canon XXXVI.

Let the throne of Constantinople be next after that of Rome, and enjoy equal privileges.  After it Alexandria, then Antioch, and then Jerusalem.

Balsamon.

The Fathers here speak of the Second and Third canons of the Second Synod [i.e. I. Constantinople] and of canon xxviij. of the Fourth Synod [i.e. Chalcedon].  And read what we have said on these canons.

Aristenus.

We have explained the third canon of the Synod of Constantinople and the twenty-eighth canon of the Synod of Chalcedon as meaning, when asserting that the bishop of Constantinople should enjoy equal privileges after the Roman bishop, that he should be placed second from the Roman in point of time.  So here too this preposition “after” denotes time but not honour.  For after many years this throne of Constantinople obtained equal privileges with the Roman Church; because it was honoured by the presence of the Emperor and of the Senate.

On this opinion of Aristenus’s the reader is referred to the notes on Canon iij. of I. Constantinople.

Justinian.

(Novella CXXXI., Cap. ij.)

We command that according to the definitions of the Four Councils the most holy Pope of Old Rome shall be first of all the priests.  But the most blessed Archbishop of Constantinople, which is New Rome, shall have the second place after the Holy Apostolic See of Old Rome.

This canon, in a mutilated form, is found in the Corpus Juris Canonici, Gratian’s Decretum, Pars I., Dist. XXII., c. vj.