Diocletian

Diocletian created the Tetrarchy, dividing the Roman Empire into four administrative regions ruled by two senior emperors (Augusti) and two junior emperors (Caesares). This system aimed to improve governance and defense, and stabilize imperial succession.

Diocletian reorganized the Roman provinces into smaller units (dioceses) grouped into four prefectures, separating civilian and military authority. This reform improved tax collection and administration, but also increased bureaucracy.

Diocletian issued the Edict on Maximum Prices, setting price ceilings on over 1,000 goods and services to combat inflation. The edict was largely ineffective and led to black markets, but demonstrated the state's attempt to control the economy.

Diocletian issued a series of edicts ordering the persecution of Christians throughout the Roman Empire. Churches were destroyed, scriptures burned, and Christians were executed or forced to sacrifice to Roman gods. This was the last and most severe state-sponsored persecution.

Diocletian voluntarily abdicated the throne, retiring to his palace in Split (modern Croatia). He forced his co-emperor Maximian to do the same, setting a precedent for orderly succession, though the Tetrarchy soon collapsed after his departure.