Intermittent wars have occurred between the Lombards, or Langobards, and the Gepidae, who are allied to Constantinople, from 536.

When Alboin succeeds his father, Audoin, about 563 or 565, the Lombards occupy Noricum and Pannonia (now in Austria and western Hungary), while their long-standing enemies the Gepidae border them on the east in Dacia (now Hungary).

As is customary among the Lombards, Alboin had taken the crown after an election by the tribe's freemen, who traditionally select the king from the dead sovereign's clan.

Shortly afterwards, in 565, a new war erupts with the Gepids, now led by Cunimund.

According to multiple sources, the former king, Thurisind,had been Cunimund's own father, and the enmity that both had for the Lombards was allegedly partly a result of Alboin's murder of Cunimund's brother (Thurisind's son), Turismod.

The true cause of the conflict is uncertain, as the sources are divided; the Lombard Paul the Deacon accuses the Gepids, while the Byzantine historian Menander Protector places the blame on Alboin, an interpretation favored by historian Walter Pohl.

An account of the war by the Byzantine Theophylact Simocatta sentimentalizes the reasons behind the conflict, claiming it originated with Alboin's vain courting and subsequent kidnapping of Cunimund's daughter Rosamund, that Alboin proceeded then to marry.

The tale is treated with skepticism by Walter Goffart, who observes that it conflicts with the Origo Gentis Langobardorum, where she was captured only after the death of her father.

The Gepids obtain the support of the Emperor in exchange for a promise to cede him the region of Sirmium, the seat of the Gepid kings.

Thus, in 565 or 566, Justinian's successor Justin II sends his son-in-law Baduarius as magister militum (field commander) to lead an imperial army against Alboin in support of Cunimund, ending in the Lombards' complete defeat.