List of Heads of State in 303 - 304 - List of Heads of State in 305 - List of Heads of State by Year
Africa
- The kingdom of Meroitsa (Cush) —Iesbeheamani , king ( 286-306 )
Asia
- Armenia - Tiridat III , King ( 287 - 330 )
- Wakataka - Pravarasena I , Emperor ( 270 - 330 )
- Gassanid - Al-Kharit I Ibn Talabah , King ( 287 - 307 )
- Gupta - Ghatotkacha , Maharaj ( 280-319 )
- Dhanyavadi - Tyuria Rupa , King ( 298 - 313 )
- Western Kshatrapa -
- Viswasena , Mahakshatrap ( 295 - 304 )
- Rudrasimha II , Mahakshatrap ( 304 - 348 )
- Iberia - Mirian III , King ( 284 - 361 )
- China ( Period of Sixteen Barbaric States ) -
- West Jin -
- Hui-di (Sima Zhong), the emperor ( 290 - 307 )
- Syma Ai , Regent ( 302 - 304 )
- Syma Ying , Regent ( 304 )
- Sima Yun , Regent ( 304 - 306 )
- Northern Han - Liu Yuan , Emperor ( 304 - 310 )
- Cheng - Li Xiong , Emperor ( 303 - 334 )
- West Jin -
- Korea ( Three States Period):
- Kai Confederation - Kojil , Van ( 291 - 346 )
- Koguryeo - Michon , Thevan ( 300 - 331 )
- Paekche -
- Punso , King ( 298 - 304 )
- Piru , King ( 304 - 344 )
- Silla - Kirim , Isagim ( 298 - 310 )
- Kushan Kingdom - Vasudeva II , King ( 290 - 310 )
- Lakhmida (Hira) - Imru ul-Qais I ibn Amr , king ( 295 - 328 )
- Pagan - Ying Min Pike , King ( 299 - 324 )
- Persia (Sassanids) - Ormizd II , Shahinshah ( 302 - 309 )
- Rajarata -
- Mahasena , King ( 277 - 304 )
- Sirimeghavanna King ( 304 - 332 )
- Toba - Toba Luguan , Leader ( 294-307 )
- Champa - Fan Yi , Prince ( 284 - 336 )
- Himyar - Yasir Yukhanʻim II , King ( 300 - 310 )
- Chera - Ilakadungo , King ( 287 - 317 )
- Japan - Odzin , the emperor ( 270 - 310 )
Europe
- Bosporan Kingdom -
- Fofors King ( 278-309 )
- Rescuporide VI , the king ( 303 - 342 )
- Dumnonia - Caradoc the ruler ( 290-305 )
- Ireland - Fiah Sraybtine , High King ( 285 - 322 )
- Roman Empire (Tetrarchy) -
- East -
- Diocletian , Roman Emperor (Augustus) ( 284 - 305 )
- Galerius , the Roman emperor (Caesar) ( 293 - 305 )
- West -
- Maximian , Roman Emperor (Augustus) ( 286 - 305 )
- Constantius Chlorine , Roman Emperor (Caesar) ( 293 - 305 )
- East -
Diocletian
284-305
Roman Emperor (East)Maximian
286-305
Roman Emperor (West)Hormizd II
302-309
Shahinshah PersiaOdzin
270-310
Japanese emperorMirian III
284-361
King of iberia