Time Line 303
Births
- 20,000 Martyrs of Nicomedia
- Martyrs of Caesarea
- Martyrs of Caesarea
- Martyrs of Nicomedia
- Martyrs of Nicomedia
- Martyrs of Nicomedia
- Martyrs of Nicomedia
- Martyrs of Novellara
- Martyrs of Nyon
- Martyrs of the Salarian Way
- Martyrs of Upper Egypt
- Saint Aaron of Caerleon
- Saint Aceolus of Amiens
- Saint Adaucus of Phrygia
- Saint Agapes of Nicomedia
- Saint Agapius of Caesarea
- Saint Agathopus the Deacon
- Saint Alexander of Caesarea
- Saint Alexander of Nicomedia
- Saint Anastasius of Lérida
- Saint Anastasius of Nicomedia
- Saint Anthes of Salerno
- Saint Anthimos of Nicomedia
- Saint Anthimus of Rome
- Saint Apollo of Novellara
- Saint Aquilinus of Noyon
- Saint Arontius of Potenza
- Saint Audactus of Thibiuca
- Saint Barulas
- Saint Bono of Novellara
- Saint Calamanda of Calaf
- Saint Camerinus of Sardinia
- Saint Caprasius of Agen
- Saint Cassiano of Novellara
- Saint Castoro of Novellara
- Saint Christeta of Avila
- Saint Cisellus of Sardinia
- Saint Clement of Ancyra
- Saint Crescentinus
- Saint Cyriacus of Nicomedia
- Saint Cyriacus the Martyr
- Saint Damiano of Novellara
- Saint Diocletius of Osimo
- Saint Dionisio of Novellara
- Saint Dionysius of Caesarea
- Saint Domna of Nicomedia
- Saint Domna of Nicomedia
- Saint Domnina of Anazarbus
- Saint Doroteo of Nicomedia
- Saint Dorotheus of Nicomedia
- Saint Egdunus
- Saint Ephysius of Sardinia
- Saint Esmaragdus of Nicomedia
- Saint Eugene of Nicomedia
- Saint Euthymius of Nicomedia
- Saint Eutropia of Palmyra
- Saint Evetius of Nicomedia
- Saint Exuperantius of Spoleto
- Saint Faustina of Cyzicus
- Saint Felice of Tubzak
- Saint Felicissimus of Todi
- Saint Felix of Gerona
- Saint Felix of Thibiuca
- Saint Firminus of Amiens
- Saint Florentius of Osimo
- Saint Fortunatus of Potenza
- Saint Fortunatus of Salerno
- Saint Fortunatus of Thibiuca
- Saint Gaius of Salerno
- Saint Glycerius of Nicomedia
- Saint Gorgonio of Nicomedia
- Saint Gorgonius of Nicomedia
- Saint Heraclius of Todi
- Saint Heradius of Noyon
- Saint Hilary of Nicomedia
- Saint Indes of Nicomedia
- Saint Januarius of Sassari
- Saint Januarius of Thibiuca
- Saint John of Nicomedia
- Saint Julitta of Caesarea
- Saint Justus of Trieste
- Saint Largus
- Saint Leonida of Novellara
- Saint Leonides of Palmyra
- Saint Libya of Palmyra
- Saint Lucilla of Novellara
- Saint Luxorius of Sardinia
- Saint Marcellus of Spoleto
- Saint Mardonius of Nicomedia
- Saint Mardonius of Rome
- Saint Mariano of Acerenza
- Saint Marianus of Nicomedia
- Saint Maurus of Rome
- Saint Maximus of Nicomedia
- Saint Migdonius of Rome
- Saint Mígdonus of Nicomedia
- Saint Olympiades
- Saint Pancharius of Nicomedia
- Saint Paphnutius of Egypt
- Saint Papias of Rome
- Saint Paul of Noyon
- Saint Paulillus of Nicomedia
- Saint Paulinus of Todi
- Saint Pausis of Caesarea
- Saint Peter of Nicomedia
- Saint Peter of Nicomedia
- Saint Peter the Librarian
- Saint Philoterus
- Saint Poliano of Novellara
- Saint Protus of Sassari
- Saint Romulus of Caesarea
- Saint Sabina of Avila
- Saint Sabinian of Potenza
- Saint Sabino of Spoleto
- Saint Saturninus of Cagliari
- Saint Secundus of Nicomedia
- Saint Septimus of Thibiuca
- Saint Serenus the Gardener
- Saint Sindimius of Nicomedia
- Saint Sisinius of Osimo
- Saint Smaragdus
- Saint Tecla of Novellara
- Saint Teodora of Novellara
- Saint Theodosia of Caesarea
- Saint Theodulus the Lector
- Saint Theophila of Nicomedia
- Saint Theophilus of Nicomedia
- Saint Timolaus of Caesarea
- Saint Venustian of Spoleto
- Saint Vespasiano of Novellara
- Saint Victor of Nicomedia
- Saint Vincent of Avila
- Saint Zeno of Nicomedia
Founded
Elevations
Other Events
- Diocletian begins a persecution of Christians
- Roman edict for the persecution of Christians issued by Emperor Valerius Maximianus Galerius
| 302 | 304 |