The Koinon remained semi-independent until the provincial reforms of Roman Emperor Diocletian in 297.

During this period, the Roman Emperor Diocletian wanted to marry a beautiful girl and he sent others to search for the most beautiful woman.

The Roman Emperor Diocletian came from this region.

Established by Roman Emperor Diocletian in 314, the province's capital was Perinthus.

Tiridates owed his position to the Roman Emperor Diocletian, a noted persecutor of Christianity.

At the end of the 3rd century, the Roman Emperor Diocletian undertook a vast administrative reorganization and land-survey.

Peter's time as bishop included severe persecution of Christianity from Roman Emperor Diocletian, which began in 303, and continued intermittently over the next ten years.

The Roman Emperor Diocletian tried to set maximum prices for all commodities in the end of the 3rd century CE, but with little success.

Tiburtius lay hidden during the persecution by Roman Emperor Diocletian in his father's house.

Roman Emperor Diocletian launched the bloodiest campaign against Christians that the empire had witnessed.