The Castle of Rovereto was built at the end of the 13th century by the Castelbarco family as a lookout post to guard the Adige Valley. Its strategic position allowed simultaneous control of the routes running through the Vallagarina (connecting north and south) and the Vallarsa (linking the Adige Valley with Vicenza).  

The castle’s current pentagonal shape dates back to the Venetian domination of the Lagarina region (1416-1509). In 1487, during the war between Venice and Archduke Sigismund of Austria, Count of Tyrol, the castle withstood a grueling 37-day siege, surrendering only after being severely damaged by artillery fire. Quickly reclaimed by the Venetians, the fortress was rebuilt, transforming its pre-existing medieval layout. The structure is considered one of the most significant examples of transitional-era military architecture. It features a siege well, robust defensive walls, and bastions equipped with dozens of gun ports, owing its impressive appearance to skilled Venetian military architects such as Giacomo Coltrino and Bartolomeo d’Alviano. During Venetian rule, the castle served as the residence of a castellan, while a podestà administered justice in the Palazzo Pretorio, located in the square below.  

After Venice's defeat at Agnadello in 1509, Rovereto came under the rule of the Austrian Empire. Having lost its strategic importance, the castle fell into neglect, suffering significant alterations and fires, the last of which occurred in 1797. During the 19th century, it was used as a shelter for the destitute, a prison, and, from 1859 to 1918, as the headquarters for two companies of the 3rd Kaiserjäger Regiment.  

During the First World War, from the evacuation of Rovereto in May 1915 to November 1918, the castle and the city, still under Austrian control, were heavily bombarded by Italian artillery.  

Restored in the 1920s, the castle has housed the Italian War History Museum since 1921. Since 2001, the castle has been undergoing an extensive restoration project led by the Superintendence for Cultural Heritage of the Autonomous Province of Trento, in collaboration with the Municipality of Rovereto.