Valentinus was a Roman figure of the later fourth century AD.
In 369 AD he committed an unrecorded but very serious crime. His brother in law, Maximinus was close to the emperor Valentinian I and was able to have Valentinus' sentence commuted from execution to exile and he was sent to Roman Britain.
On arrival, he soon made contact with other exiles in the province and they began planning a revolt that involved bribing the local troops to side with them during the chaos of the Great Conspiracy.
When Count Theodosius arrived to crush the Great Conspiracy he acted quickly to put down Valentinus' revolt before it could begin. He and his circle of exiles were handed over to the new Dux Britanniarum, Dulcitius for execution. Unusually, there was very little further investigation into the revolt and attempts were made to smooth over relations in the province following the restoration of peace.
Valentinus' story illustrates the instability in Roman Britain at the time, the widespread discontent with Roman rule and the lengths that Theodosius was prepared to go to keep the peace.