The Limes was not secure even after constructing the new vast fortification system. After a serries of new attacks of Quadi and Sarmatians, one more attempt to˙protect and strenghten the position of Romans in Pannonia was undertaken by the Emperor Valentinian I. - the last Emperor born in Pannonia (364-375 AD). In the frames of his widespread fortification programme was, apart of the traditional reconstruction works, also constructed a dense chain of watch-towers. Other important activities were carried out too. For the secure supply of the army via the Danube as a route, the embankments were constructed, the ports were fortified by towers and new fortifications were set up on the bank belonging to barbarian tribes. This reised a revolt among the Quadi inhabitants. After the assassination of their King Gabinius, they together with their old allies Marcomanni and Sarmatians, broke through the Limes and invaded the province. As a reaction, in spring of 375 AD, Valentinian I. led a penal and succesfull campaign against Quadi. During the negotiations following his victory, carried in Brigetio in November of the same year, the demands of Quadi made him so upset, that he got a stroke and suddenly died.

Radical changes in the political situation came after the death of Valentinian I. While the attacs of Quadi and Sarmatians threatened Pannonia, the pressure of the Gothi tribes on the Lower Danube endangered security and existence of the entire Roman Empire. The war that broke out in 367 and the defeat of the Romans at Hadrianopolis opened a new chapter in the history. Borderes were not further protected, and the waves of barbarian tribes penetrated the territorry. The numbers of romanised inhabiatants decreased what led to the end of romanisation and general fall. The attempts of the reorganisation of the military forces and reoccupation of some lost territories in Pannonia finally failed under the increasing pressure of the barbarian tribes and the attack of Huns. Since 433 a large territory of Pannonia was appeared under the rule of Huns and from than on the events in Pannonia were determined by the development of Hun-Roman relationship.

The building of the North-Pannonian border

The Roman Army

The armament and equipment of the Roman Soldiers

The role and importance of the Roman Army

Marcomannic wars on the Danube

The period of prosperity and decline