Before the creation of this province, its territory was part of the province of Pannonia Inferior. In the year 296, Pannonia Inferior was divided into two provinces - Pannonia Secunda in the south and Pannonia Valeria in the north. The border between the two newly established provinces was the River Drava.
The capital of Pannonia Secunda, Sirmium, was also one of the four capitals of the Roman Empire; several Roman emperors were born in or near this city.
In the year 314, there was a battle between two pretenders to the imperial throne, Constantine the Great and Licinius. The battle occurred in Pannonia Secunda, near the town of Cibalae. Constantine had an army of 20,000 men, while Licinius had 35,000. The battle lasted for the whole day and Constantine was victorious.
Besides Sirmium, the other cities in Pannonia Secunda were: