Few off-screen romantic battles match the triangle of love-hate between Roberto Rossellini, Anna Magnani, and Ingrid Bergman, but Italian filmmaker Francesco Patierno’s documentary Bergman & Magnani: The War of the Volcanoes is very possibly the first film to meticulously track the charged events of 1950, when Rossellini cast his new amore Bergman in Stromboli just as his ex-lover Magnani was filming Vulcano under William (Kismet) Dieterle’s direction on a neighboring Aeolian island.

A tale of broken hearts and stolen story ideas, this avventura begins with Rossellini and Magnani’s extremely volatile relationship, initiated during the making of the director’s early masterpiece, Roma, città aperta. As needy as Rossellini was mercurial, Magnani had little patience for the director’s roving eye. But a new project, suggested to Rossellini by a group of young filmmakers based in the Aeolians, seemed to offer an ideal role for the extraordinarily powerful depths of Magnani’s acting genius.

Amassing and molding a rich vein of archival footage, Patierno and editor Renata Salvatore create a fascinating back-and-forth narrative as Rossellini and Magnani go head to head with the competing projects. The director swoons over Bergman—whose contrasts in body and spirit to Magnani are telling—and manages (with Bergman’s help) to land Howard Hughes as producer. Meanwhile, the Aeolian lads, enraged that Rossellini apparently went behind their back to film their ideas, produce Vulcano with Magnani and Dieterle. The alternating tracks of the two projects contain fascinating parallels (both experienced disastrous premieres), and, although Vulcano has long been forgotten, the incredibly arduous making of Stromboli suggested a far more flawed film (Hughes threatened to pull the plug more than once). Film history, however, has delivered a different verdict.