According to the first collections in which the letter was preserved, it was addressed to the presbyters and deacons of Rome who travelled to Ravenna. Later collections presumed that Zosimus wrote to the clergy of Ravenna. The first alternative is to be preferred (Dunn 2016: 6). In fact, we can see in the letter two groups of Roman clerics who went to Ravenna: the "rebels" (only presbyters), and the second group, loyal to Zosimus, to whom he addressed his letter.
The "rebellious" presbyters went to the imperial court with some grudges against Zosimus, possibly in relation to the seeming support of the pope for Pelagianism.
It is not clear which canons Zosimus was thinking of when he said that they prohibit the presbyters from appealing to the emperor.
The tensions within the Roman clergy at the time resulted in the double election of the successor of Zosimus after his death in AD 418, when both Deacon Eulalius and Presbyter Boniface [225] were elected.
Presbyter Archidamus, who is mentioned at the beginning of the letter and who informed Zosimus about the situation, is probably the same who carried the letter of Pope Innocent I to Africa in AD 413 [1707].