Constantius I was made Caesar in 293 by Diocletian. He defeated the rebel Allectus and brought Gaul and Britain back under control of Rome. He was married to Saint Helen and was Constantine the Great’s father. After the abdication of Diocletian and Maximianus in 305, Constantius and Galerius were made Augusti. Constantius died in York in 306, whereupon his son Constantine the Great was proclaimed emperor by the troops at York.