The Sicilian antipasto relish known as caponata is said to be of Spanish origin. The Sicilian food authority Pino Correnti believes that the dish is derived from the Catalan word caponada, meaning a similar kind of relish, and says it first appears in a Sicilian etymology of 1709. This Catalan word, which literally means "something tied together like vines," can also refer to an enclosure where animals are fattened for slaughter. But the root word capón figures in the expression capón de galera which is a gazpacho or a caponata-like dish usually served shipboard. According to Juan de la Mata in his Arte de reposteria published in 1747, the most common gazpacho was known as capón de galera consisting of a pound of bread crust soaked in water and put in a sauce of anchovy bones, garlic, and vinegar, sugar, salt and olive oil and letting it soften. Then one adds "some of the ingredients and vegetables of the Royal Salad [a salad composed of various fruits and vegetables]."
Alberto Denti di Pirajno, the learned Sicilian scholar, medical doctor, and gastronome, suggested that the dish was born shipboard as a mariner's breakfast because of the large amount of vinegar used, which would have acted as a preservative. Giuseppe Coria, author of an authoritative tome on Sicilian cooking, offers another suggestion: That the word derives from the Latin word caupo (tavern) where cauponae was served, that is, tavern food for travelers. Even if this interpretation is correct, cauponae certainly wasn't the caponata we know today.
The earliest recipe I am familiar with of a dish that is a kind of caponata is the cappone di galera alla siciliana in Francesco Leonardi's L'Apicio moderno (The modern Apicius) published in 1790. Here is his recipe: