Gaeta's layered history — Roman, medieval, Bourbon, and Risorgimento — sits within a richly documented region. These titles help place the town in its broader context.
The Aeneid by Virgil remains the foundational text for the whole Lazio coast. Virgil names Gaeta directly: Caieta, nurse of Aeneas, is buried here, and the promontory takes its name from her. Any edition with good notes will illuminate the landscape you're walking through.
Mary Taylor Simeti's On Persephone's Island (1986) is a memoir of living in southern Italy that conveys the rhythms of food, seasons, and local identity that apply equally well to the towns along the Gulf of Gaeta. Her later Pomp and Sustenance is a history of Sicilian food that provides deep context for the cucina of the whole Tyrrhenian coast — including the tiella tradition.
For the Risorgimento period, Christopher Duggan's The Force of Destiny: A History of Italy Since 1796 covers the siege of Gaeta (1860–61), the last stand of the Bourbon Kingdom of the Two Sicilies, in accessible prose. Gaeta was the final fortress to fall to the armies of the new united Italy.