• Augustus, 27 BC–14
• Tiberius, 14–37
• Caligula, 37–41
• Claudius, 41–54
• Nero, 54–68
• Vespasian, 69–79
• Titus, 79–81
• Domitian, 81–96
• Trajan, 98–117
  • correspondence between Trajan and Pliny the Younger
• Hadrian, 117–138
• Antonius Pius, 138–161
• Marcus Aurelius, 161–177
  • with Lucius Verus, 161–169
  • with Commodus, 177–180
• Commodus, 180–192
• Septimius Severus, 193–211
  • Pertinax, 193
  • Didius Julianus, 193
  • with Cara calla
  • with Cara calla and Geta, 209–211
  • with Geta, 211
• Geta, 209–211
• Cara calla, 211–217
• Macrinus with Diadumenian, 217–218
• Elagabalus, 218–222
• Severus Alexander, 222–235
• Maximinus the Thracian, 235–238
• Gordian I & II, 238
• Gordian III, 238–244
• Philip the Arab, 244–249
• Decius, 249–251
• Valerian with son Gallienus, 253–260
• Aemilianus, 253
• Gallienus 253–268
• Aurelian, 270–275
• Diocletian, 284–305
• Constantine I, 306–337
  • Constantine issues Edict of Milan, later signed by Licinius as well
  • Constantine writes about the Donatist Schism, c. 320
  • Constantine calls the Council of Nicaea, 325
• Constantius II, 337–361
  • followed Arianism
• Julian the Apostate, 360–363
• Valens, 364–378
  • persecuted non-Arians
• Gratian, 367–383
• Theodosius, 379–395

• Council of Carthage, 220–225
  • key issue: validity of baptisms performed by heretics
  • declared baptisms performed by heretics to be invalid
• opens new windowCouncil of Nicaea (1st : 325), 1st ecumenical council
  • condemned Arianism
  • proclaimed the Son to be homoousion ("of one substance") with the Father
  • proclaimed the original Nicene Creed written by Athanasius, not to be confused with the later Nicaeo-Constantinopolitan Creed
  • pope, Sylvester I; and emperor, Constantine the Great
• opens new windowCouncil of Constantinople (1st: 381), 2nd ecumenical council
  • key issue: homousian (of the same essence or substance) or homoiusian (of similar or like essence or substance)
  • condemned Apollinarianism, Eunomianism, Sabellianism, and Macedonianism
  • adopted the Nicaeo-Constantinopolitan Creed, often commonly referred to as the Nicene Creed as distinguished from the Apostle's Creed
  • pope, Damascus I; and emperor, Theoldosius the Great
• opens new windowCouncil of Ephesus, 431, 3rd ecumenical council
  • key participants: Cyril of Alexandria, Memnon of Ephesus, Juvenal of Jerusalem, Candidianus
  • key issue: Nestorius' rejection of Theotokos
  • pope, Celestine I; emperor, Theodosius II
• opens new windowCouncil of Chalcedon, 451 (4th ecumenical council)
  • approved the creeds of both 325 and 381
  • approved Cyril's two letters against Nestorius and Leo I's tome
  • affirmed the unity in one person of Christ's divinity and humanity
  • affirmed Christ's two natures against Monophysitism, which affirmed only one
  • condemned Eutychianism
  • pope, Leo I, the Great; emperor, Marcian
• Council of Orange, 529
• Council of Constantinople (2nd: 553), 5th ecumenical council
  • condemned the "Three Chapters"
  • pope, Vigilius; emperor, JustinianI
• Council of Constantinople (3rd: 680), 6th ecumenical council
  • condemned Monothelitism
  • pope, Agatho; emperor, Constantine IV
• opens new windowCouncil of Nicaea (2nd: 787), 7th ecumenical council
  • condemned iconoclasm
  • pope, Hadrian I; emperor, Constantine VI

Nero, 64

• martyrs: Peter and Paul

Domitian, c. 90–96

• martyr: Clement
• exile: John

Trajan, 98–117

• martyrs: Ignatius (c. 110), Symeon, Rufus

Hadrian, 117–138

Antoninus Pius, 138–161

• martyr: Polycarp

Marcus Aurelius, 161–180

• martyrs: Justin Martyr, Scillitan martyrs
  • Acts of the Scillitan Martyrs

Septimus Severus, 202–211

• martyrs: Leonidas, Irenaeus, Perpetua

Maximinus the Thracian, 235–236

• martyrs: Ursula, Hippolytus

Decius, 249–251

• required everyone (except Jews) to sacrifice to the gods
• reason Cyprian went into hiding for a time
• as a result of the apostasies that occurred, led to rise of Novatianism
• martyr: Alexander of Jerusalem

Valerian, 257–260

• martyrs: Origen, Cyprian, SixtusII​, and Novatian

Diocletian/Galerius, 303–311

• led to Donatism