Letter LIII is a fragment — a single surviving paragraph from a longer letter in which Anatolius of Constantinople presented himself and his election to Leo. Anatolius had been installed as Bishop of Constantinople after the events of Ephesus II: Flavian, the legitimate bishop, had been condemned and deposed by the council in August 449 and died shortly afterward, apparently from injuries sustained during the proceedings. Anatolius was the candidate backed by Dioscorus of Alexandria, and his installation was the concrete expression of the new ecclesial order that the Latrocinium had attempted to impose on the Eastern church.

That Anatolius writes to Leo at all — presenting himself, explaining his election, implicitly seeking recognition — is itself a primacy acknowledgment. Even a bishop placed in Constantinople by Dioscorus’s faction understood that the question of whether the Apostolic See would recognize him was not trivial. Leo’s recognition mattered, and its absence would cost Anatolius something real. The letter therefore belongs to the project’s pattern of Eastern bishops acknowledging Roman authority even when they had every reason to operate independently of it. Leo’s subsequent dealings with Anatolius were cautious and conditional: recognition came, but not without Anatolius being required to demonstrate orthodox credentials, including his relationship to the Tome.

The account of the election itself is worth noting. The process Anatolius describes is thoroughly imperial: Theodosius drove the proceedings, reserved the initial selection to himself, ordered candidates from outside Constantinople to be considered, and only afterward permitted the clergy to elect. Anatolius presents this without apparent discomfort, and in that there is a contrast with Leo’s consistent insistence that ordinations require the consent of clergy and people and must not be imposed by outside authority — a principle expressed most forcefully in Letter X in the Hilary of Arles affair and reiterated in the post-Latrocinium correspondence. The reader will find that when Leo eventually achieves the reconvening of a proper council at Chalcedon in 451, the question of how bishops are properly appointed — by ecclesiastical process or by imperial fiat — is among the underlying tensions that the council must resolve.

The fragment closes with Anatolius attributing his election entirely to God’s providence operating through his own unworthiness — a conventional humility formula, but one that here carries the additional weight of the circumstances. The “great dissension” he alludes to within the Constantinopolitan clergy is the residue of the Eutychian controversy: the city’s clerical community was fractured, and it required imperial authority to move the process forward at all. The see into which Anatolius was installed was not a peaceful inheritance.