** Battle of Lingones — Caesar Constantius Chlorus defeats the Alemanni

Soon after his father's death Constantius is supposed to have ordered a massacre of his relatives descended from the second marriage of his paternal grandfather Constantius Chlorus, though the details are unclear.

In 293, Constantius Chlorus launched a second offensive, besieging the rebel's port at Boulogne and cutting it off from naval assistance.

Constantius Chlorus returned in 306, aiming to invade northern Britain.

His paternal grandparents were Western Roman Emperor Constantius Chlorus and his second wife, Flavia Maximiana Theodora.

Constantius II ordered the murders of many descendants from the second marriage of Constantius Chlorus and Theodora, leaving only Constantius and his brothers Constantine II and Constans I, and their cousins, Julian and Gallus ( Julian's half-brother ), as the surviving males related to Emperor Constantine.

* 293 – Roman Emperors Diocletian and Maximian appoint Constantius Chlorus as Caesar to Maximian.

* 250 – Constantius Chlorus, Roman Emperor ( d. 306 )

In 293, feeling more focus was needed on both civic and military problems, Diocletian, with Maximian's consent, expanded the imperial college by appointing two Caesars ( one responsible to each Augustus ) — Galerius and Constantius Chlorus.

* Augusta Treverorum ( modern Trier, in Germany ) was the capital of Constantius Chlorus, the western Caesar, near the strategic Rhine border, it had been the capital of Gallic emperor Tetricus I ; this quarter became the prefecture Galliae.

Their Caesares, Galerius and Constantius Chlorus, were both raised to the rank of Augustus, and two new Caesares were appointed: Maximinus ( Caesar to Galerius ) and Flavius Valerius Severus ( Caesar to Constantius ).

:: Gallia et Hispaniae Constantius Chlorus ( 293 – 305 )

:: Gallia, Hispaniae et Britannia Constantius Chlorus ( 305 – 306 )

The first book sketches briefly the history of the early Roman emperors from Augustus to Diocletian ( 305 ); the second, third and fourth deal more fully with the period from the accession of Constantius Chlorus and Galerius to the death of Theodosius I ; the fifth and sixth, the most useful for historians, cover the period between 395 and 410, when Priscus Attalus was deposed ; for this period, he is the most important surviving non-ecclesiastical source.

Constantius Chlorus requests leave for his son Constantine I who remains at Galerius's court in Nicomedia, as a virtual hostage.

* Battle of Lingones: Constantius Chlorus defeats the Alamanni in the territory of the Lingones ( Langres ) in Gaul.

* Constantius Chlorus defeats the Alemanni and fortifies the town of Konstanz ( Germany ).

Medal of Constantius Chlorus capturing Roman London | Londinium ( 296 )

* Constantius Chlorus assembles two invasion fleets with the intent of crossing the English Channel.

* Constantius Chlorus reconquers Britain, he rebuilds the cities Eboracum ( York ), Londinium ( London ), and Verulamium ( St Albans ).

Diocletian delegated further on 1 March 293, appointing Galerius and Constantius as Caesars, junior co-emperors.

The senior co-Emperors formally adopted Galerius and Constantius as sons in 293.

Galerius and Constantius would become Augusti after Diocletian and Maximian's departure.

In 305, the senior emperors jointly abdicated and retired, allowing Constantius and Galerius to be elevated in rank to Augusti.

They in turn appointed two new Caesars — Severus II in the west under Constantius, and Maximinus in the east under Galerius — thereby creating the second Tetrarchy.

When Constantius died in 306, Galerius promoted Severus to Augustus while Constantine the Great was proclaimed Augustus to succeed his father Constantius, by his father's troops.

A chart of the tetrarchy from 305 to 306, after the retirement of Diocletian and his colleague Maximian, and the accession of Constantius I | Constantius and Galerius.

* March 1 – Emperor Diocletian and Maximian appoint Constantius Chlorus and Galerius as Caesars.

Constantius was the more senior of the two Caesars, and on official documents he always took precedence, being mentioned before Galerius.

Instituted by Diocletian, it was avidly pursued by Galerius who noticed that Constantius was well disposed towards the Christians, and saw it as a method of advancing his career prospects with the aging Diocletian.

Between 303 and 305, Galerius began maneuvering to ensure that he would be in a position to take power from Constantius after the passing of Diocletian.

In 304, Maximian met up with Galerius, probably to discuss the succession issue and Constantius either was not invited or could not make it due to the situation on the Rhine.

Although prior to 303 there appeared to be tacit agreement between the Tetrarchs that Constantius ’ s son, Constantine and Maximian ’ s son Maxentius were to be promoted to the rank of Caesar once Diocletian and Maximian had resigned the purple, by the end of 304 Galerius had convinced Diocletian ( who in turn convinced Maximian ) to appoint Galerius ’ s nominees Severus and Maximinus Daia as Caesars.

Constantius, notionally the senior emperor, ruled the western provinces, while Galerius took the eastern provinces.

Constantine, disappointed in his hopes to become a Caesar, fled the court of Galerius after Constantius had asked Galerius to release his son as Constantius was ill. Constantine joined his father's court at the coast of Gaul, just as he was preparing to campaign in Britain.

" The great councils of 359 – 60 are therefore not reckoned ecumenical in the tradition of the church, and Constantius II is not remembered as a restorer of unity, but as a heretic who arbitrarily imposed his will on the church.

* The Lentienses, a Germanic tribe, are fined by the Roman commander Arbetio under Constantius II for several incursions against the Roman Empire.

Constantius leaves with his fleet Boulogne and occupies London, saving the city from an attack by Frankish mercenaries who are roaming the province.

* Ministers and followers of Constantius II are put to trial at the Chalcedon tribunal.

* September – A number of descendants of Constantius Chlorus and officials of the Roman Empire, are executed.

On the reverse of this argenteus struck in Antioch under Constantius Chlorus, the tetrarchy | tetrarchs are sacrificing to celebrate a victory against the Sarmatia ns.

Comparing this material with Constantius of Lyon ' Life of St. Germanus of Auxerre, it suggests that the two are not the same person.

The sources are equivocal on the point, sometimes calling Helena Constantius ' " wife ", and sometimes, following the dismissive propaganda of Constantine's rival Maxentius, calling her his " concubine ".

Others, like Timothy Barnes, assert that Constantius and Helena were joined in an official marriage, on the grounds that the sources claiming an official marriage are more reliable.

Some sources, among whom are Joannes Zonaras, claim that this plot had been organized by Magnentius in order to distract Constantius from Magnentius himself.

In 305, Constantius Chlorus re-invaded the northern lands of Britain although the sources are vague over their claims of penetration into the far north and a great victory over the " Caledones and others " ( Panegyrici Latini Vetares, VI ( VII ) vii 2 ).

The Battle of Adrianople in 378, the death of Theodosius I in 395 ( the last time the Roman Empire was politically unified ), the crossing of the Rhine in 406 by Germanic tribes, the execution of Stilicho in 408, the sack of Rome in 410, the death of Constantius III in 421, the death of Aetius in 454, the second sack of Rome in 455, and the death of Majorian in 461 are emphasized by various historians.

* Εὐστάθιος ( Eustáthios ) meaning " steadfast ", " stable "; literally " possessing good stability "; its exact Latin equivalents are Constans and its derivatives, Constantius and Constantinus

The Panegyrici Latini, a series of twelve speeches given in praise of Roman emperors, describe the efforts of Constantius Chlorus, father of Constantine the Great, to pacify the Franks, who are kept distinct from the Chamavi.

These Panegyrici are often attributed to Eumenius, magister memoriae ( private secretary ) to Constantius, resulting in the compromise name of pseudo-Eumenius.

Nothing is known about other marriages of Julius Constantius, but since the sources about him are rather poor, other marriages are of course not excluded.

His works are written in the form of speeches delivered directly to Constantius and repeatedly address the emperor in the second person throughout.

Also extant is a pair of letters which are allegedly correspondence between Lucifer and the emperor's secretary Florentius on the subject of some of Lucifer's inflammatory works that he had sent to Constantius.

Dioclesian begat Galerius, Galerius begat Constantine the Great the son of Helen, Constantine begat Con-stantius, Constantius begat Maximianus, with whom the British soldiers went from Britain, and he slew Gratian the Roman emperor, and held the government of all Europe ; and he did not dismiss the soldiers, which he brought with him from Britain to return to their country on account of their bravery, but gave them many provinces and countries, that is from the pool which is on the top of the mountain of Jupiter to the city named Cantguic, and until the western mound that is Cruc Ochideint ; and from those soldiers arose a nation which is called Lettau. 1 Maximianus therefore begat Owain, Owain begat Nor, Nor begat Solor, Solor begat Glywys, Glywys begat Gwynlliw, Gwynlliw begat the most blessed Cadoc of whom we are speaking.