Although Fuscus was initially successful in driving the invaders back across the border, the prefect suffered defeat when he was ambushed along with Legio V Alaudae during an expedition into Dacia, at the First Battle of Tapae.
The Roman historian Tacitus informs us that he was born into an aristocratic family, but renounced a senatorial career in favour of a life of "quiet repose" as an equestrian.
About six months earlier, Gaius Julius Vindex, the governor of Gallia Lugdunensis, had rebelled against tax policies instituted by Emperor Nero.
[4] Nero's own popularity was already on the decline, but nonetheless, he managed to crush the revolt by quickly sending the governor of Germania Superior, Virginius Rufus, to Gaul, where Vindex was defeated in a battle near Vesontio.
According to Tacitus, Fuscus was vital in acquiring the support of an unspecified Roman colony in Spain, Northern Italy, or Gaul,[9] a service for which he was rewarded with the procuratorship of Illyricum.
Not long after, the provinces of Illyricum, Pannonia and Dalmatia defected to the side of the Flavians, at the instigation of Marcus Antonius Primus and Cornelius Fuscus.
[citation needed] Sometime around 84 or 85 the Dacians, led by King Decebalus, crossed the Danube into the province of Moesia, wreaking considerable havoc and killing the Moesian governor Gaius Oppius Sabinus.
[13] The victory proved to be short-lived however, as early in 86, Fuscus embarked on an ill-fated expedition into Dacia, which resulted in the complete destruction of the fifth legion, Legio V Alaudae, near Tapae.