306, October: Maxentius usurps power in Italy, but is not recognized
307 Constantine crosses the North Sea and attacks the Franks (accepts the title Germanicus Maximus?); return to Britain (?); visits Trier, where he is recognized as augustus by Maximian, who has returned from retirement; Constantine marries Fausta, daughter of Maximian; both men recognize each other as consul
308 War against the Germans (accepts the title Germanicus Maximus II?); Constantine again recognized as caesar by the emperors who have gathered in Carnuntum; Maximian resigns and stays in Constantine's territories in souterh Gaul; Licinius appointed as emperor; Maxentius loses Africa to Lucius Domitius Alexander
309 Consul (with Licinius); Constantine build a bridge across the Rhine near Cologne
Constantine and Helius
310 Maximianus provokes a new rebellion, is captured, and commits suicide news about an insurrection of the Franks forces Constantine to return to the north; vision along the road to Andesina; Maxentius recovers Africa
310, Spring: Decennalia in Trier
311 Galerius puts an end to the persecution of Christian and dies soon after; Maximinus Daia occupies Asia Minor; growing tensions with Licinius, who allies himself to Constantine; Licinius and Constantine's sister Constantia engaged
312 Consul II (with Licinius II); Constantine crosses the Alps, attacks and defeats the usurper Maxentius at the Milvian Bridge
313 Consul III (with Licinius III); meeting of Licinius and Constantine (Edict of Milan); Licinius defeats his rival Maximinus Daia on the Campus Serenus near Adrianople; Constantine in Britain
314 Synod of Arles
Constantine, c.315
315 Consul IV (with Licinius IV); Constantine defeats the Sarmatians and Visigoths; visit to Rome; Arch of Constantine
316 Constantine decides against the Donatists; birth of Constantinus II; brief war against Licinius
317 Constantine and Licinius declare their sons Crispus, Constantinus II, and Licinius Junior caesares; birth of Constantius II
321 Crispus consul II (with Constantinus II consul II); Constantine grants tolerance to the Donatists
321, 7 March: Law to proclaim Sunday, "the venerable day of the Sun", as a day of rest
322 Defeats the Sarmatians
323 War against the Visigoths; accepts the title Sarmaticus Maximus III
323 Christians no longer forced to attend pagan ceremonies
Sole ruler
324 Crispus consul III (with Constantinus II consul III); war with Licinius; Crispus commands the navy and defeats Licinius' admiral Amandus; Licinius himself is defeated near Adrianopel and (18 September 324) Chrysopolis, flees to Asia, resigns, and is exiled to Thessaloniki; Constantius II made caesar; foundation of Constantinople
325 Execution of Licinius
Nineteenth-century painting of the Council of Nicaea (325)
325, 20 May - 19 June: First Ecumenical Council, at Nicea
326 Consul VII (with Constantius II)
326, February: fall and death of Crispus; execution of Fausta
Visit to Rome; vicennalia; the empress-mother Helen to Jerusalem
326, 18 November: Dedication of St. Peter's basilica
327 Second gathering of the Council of Nicea
327 Helena in Jerusalem
328 War against the Visigoths; accepts the title Gothicus Maximus II; Constantinus II directs a war against the Alamans
329 Consul VIII (with Constantinus II consul IV); death of Helena; war against the Visigoths; accepts the title Germanicus Maximus IV
334 Sarmatians expelled from the empire; Delmatius suppresses the revolt of Colocaerus
335 Tricennalia; Delmatius proclaimed caesar; Hannibalianus made king of the Pontic nations
336 Accepts the title Dacicus Maximus
Trier, basilica
337 Easter celebrated in Constantinople; Delmatius assassinated; Persian embassy; baptism; death
Buildings:
Rome: Santa Costanza (= mausoleum of Constantina); Arch of Constantine; Basilica of Constantine; Baths of Constantine; Baths of Helena; Saint Peter's basilica; Saint John's basilica; Saint Paul's basilica
