Surveys and surface investigations conducted in recent years have allowed to date back thousands of years the human presence in the territory of Guardiagrele, which stood no longer behind the Iron Age, with the protohistoric burials of the necropolis of Comino (IX sec. a.c.).

The oldest and most reliable document, mentioning a "villa quae vocatur Grele" among the possessions of the Benedictine monastery of San Salvatore in Maiella, is a bull of 1070 of Pope Alexander II, but of this rural settlement not fortified do not remain tangible evidence that relate to the era of foundation, which is likely to be located in late-ancient or early medieval.

About a century later, in Norman times, Grele is mentioned in the Catalogus Baronum, the lever register of the southern kingdom, as a property no longer monastic but feudal. The phase of increasing urban and artistic splendor was accelerated at the beginning of the 14th century and attracted masters such as Nicola da Guardiagrele and Andrea Delitio to the city.

The period of prosperity did not last long: from the end of the '400, the changed political and territorial conditions, marked the beginning of a slow decline. The rebirth, known after the earthquake of 1706, was interrupted in 1799 when, as part of the Napoleonic campaign, a French contingent attacked Guardiagrele which was set on fire and plundered. In more recent times it was World War II that demanded a new tribute of destruction and demolition, making it necessary to rebuild buildings that are often completely alien to the urban context and completing the irreversible transformation of an ancient medieval village into a modern city.

Today Guardiagrele, the dannunziana city of stone, is a solid reality in the historical/artistic and naturalistic heritage of the Abruzzo region. Architectural gems in stone and brick, including Santa Maria Maggiore and San Francesco, Palazzo Vitacolonna and other noble palaces with portals, windows and courtyards. The museums that best document the history and tradition of the city. The Maiella, Mother mountain that enhances the Guardiese territory with its forests, waters, paths and suggestions. All this makes Guardiagrele an excellence in the panorama of the centers of Abruzzo.