Could priests and bishops marry?

Clement of Alexandria c. 150–c. 215 ADStromata 3.6.52

Peter and Philip had children, and Philip gave his daughters in marriage. And Paul does not hesitate in one letter to speak of his wife, whom he did not take around with him for the sake of his ministry's freedom.

Written against teachers who condemned marriage. The "wife" of Paul is Clement's reading of Philippians 4:3.

Council of ElviraCanons Canon 33

It was decided to forbid entirely bishops, presbyters and deacons, or all clerics serving in the ministry, to have relations with their wives and beget children. Whoever does so shall be removed from clerical office.

The Latin is famously awkward: read literally it forbids them "to abstain". It is taken as a rule of continence for married clergy in Spain.

Paphnutius at Nicaea (as Socrates reports) fl. 325 ADSocrates, Church History 1.11.4–6

The bishops wanted to bring a new law into the Church, that those in holy orders, bishops, presbyters and deacons, should not sleep with the wives they had married while still laymen. When this was being discussed, Paphnutius stood up in the middle of the assembly of bishops and cried out not to lay a heavy yoke on the clergy, saying that marriage itself is honorable and the bed undefiled (Hebrews 13:4) ... that it was enough for those already ordained not to marry afterward, according to the Church's ancient tradition, but not to be separated from the wife they had once married as laymen.

Socrates writes a century later; some historians doubt the story. It matches the later Eastern rule: married men may be ordained, but no one marries after ordination.

SiriciusLetter to Himerius 7

We have learned that very many priests of Christ and levites, long after their consecration, have fathered children both from their own wives and even from shameful intercourse. ... By these decrees all of us, priests and levites, are bound by an unbreakable law, so that from the day of our ordination we devote both our hearts and our bodies to sobriety and chastity. ... Any bishop, presbyter or deacon who is hereafter found to be such a man, which we do not desire, must understand that every way to pardon through us is now shut to him.

Pope Siricius to Himerius of Tarragona (10 February 385), the first papal decretal on the subject: he treats clerical continence as a rule already in force, and Denzinger’s own note says the same. Levites here are deacons. Read from the scan of Denzinger’s Enchiridion (11th ed., 1911), no. 89, whose OCR is poor in places; the words quoted follow the standard text. No locked Siricius text exists in the library.

Council of CarthageCanons of the African Church Canon 3

Bishop Aurelius said: ... it was decided that the holy bishops and priests of God, and also the deacons, who serve the divine sacraments, should be continent in all things, so that they may obtain simply what they ask of the Lord; so that what the apostles taught and antiquity itself kept, we too may keep. ... All the bishops said: It is agreed that chastity be kept in all things and by all who serve the altar.

The African church claimed apostolic origin for clerical continence.

Council in TrulloCanons Canon 13

Since we know it to be handed down as a rule of the Roman Church that those who are deemed worthy to be advanced to the diaconate or presbyterate should promise no longer to cohabit with their wives, we, preserving the ancient rule and apostolic perfection and order, will that the lawful marriages of men who are in holy orders be from this time forward firm, by no means dissolving their union with their wives nor depriving them of their mutual intercourse at a convenient time. ... if anyone shall have been found worthy to be ordained subdeacon, or deacon, or presbyter, he is by no means to be prohibited from admittance to such a rank, even if he shall live with a lawful wife.

The Eastern council of 692 knew Rome's custom of separating clergy from their wives and refused it, ordering that the marriages of men in holy orders stand firm. Quoted here in Percival's standard English translation; the council's Greek text is still to be quoted when a lawful open Greek edition is secured.

Second Lateran CouncilCanons Canon 7

Following in the footsteps of our predecessors, the Roman pontiffs Gregory VII, Urban and Paschal, we command that no one hear the Masses of those whom he knows to have wives or concubines. And so that the law of continence and the purity pleasing to God may spread among ecclesiastical persons and sacred orders, we decree that bishops, priests, deacons, subdeacons, canons regular, monks and professed lay brothers who, transgressing the holy resolve, have presumed to take wives to themselves, be separated. For we judge that a union of this kind, which is known to have been contracted against the Church’s rule, is not a marriage.

The step beyond continence: a marriage contracted by a cleric in major orders is declared no marriage at all, and the couple must separate (canon 6 also strips such clerics of office and benefice). Marriages made before ordination are not touched. Latin from the published conciliar text (Tanner, Decrees of the Ecumenical Councils, vol. 1); the web page’s Latin has a copying slip later in the canon, outside the span quoted here. Denzinger’s Enchiridion prints other Lateran II canons but not this one.