The origins of the settlement are attributed to the Frentani, an Italic population, with archaeological evidence from 2005 confirming the existence of a Bronze Age settlement near the site of the current castle. During the Roman era, the town maintained its footprint over this original settlement, leaving behind remnants of paved roads and urban walls. Following the Roman period, Ortona was held by the Byzantine Empire for several centuries before its annexation by the Kingdom of the Lombards and subsequent incorporation into the county of Chieti by the Franks in 803.
The town's maritime importance grew significantly in the 13th century. In 1258, the relics of Saint Thomas the Apostle were transported to the city by the sailor Leone Acciaiuoli, establishing the Cathedral of Saint Thomas as a major religious site. The 15th century was marked by military fortification, including the construction of city walls and a defensive castle commissioned by the King of Sicily following a Venetian naval raid on the port in 1447.
The most significant military engagement in the town's history occurred in 1943 during World War II. Following the establishment of the Gustav Line by German forces, Ortona became a critical objective for Allied forces seeking a supply port on the Adriatic. The ensuing conflict between German paratroopers and the 2nd Canadian Infantry Brigade was characterized by brutal urban warfare.
The intensity of the street-to-street fighting earned the engagement the titles "Little Stalingrad" and "Western Stalingrad" in the international press. The battle resulted in the establishment of the Moro River Canadian War Cemetery and the Museum of the Battle of Ortona, which serve as the primary historical records of the conflict.
Following the unification of Italy in 1860, Ortona transitioned into one of the first sea resorts on the Adriatic. The town's modern layout is defined by a mix of historical preservation and maritime industry. Key architectural features include:
Aragona Castle: A medieval fortification overlooking the renovated port.
Palazzo Farnese: A grand mansion commissioned in 1584 by Margaret of Parma, daughter of Emperor Charles V, which remained uncompleted following her death.
Cathedral of San Tommaso: The repository for the relics of Saint Thomas the Apostle and home to the Cathedral Museum.
Trabucchi: Traditional wooden fishing machines situated along the coast.
The Port of Ortona remains a primary Adriatic transport hub. The town is geographically positioned near the Abruzzo, Lazio and Molise National Park and features several beaches that support its status as a tourist destination. On September 9, 1943, the port served as the departure point for the Italian Royal Family of the House of Savoy as they fled German-occupied Italy.
Ortona is the birthplace of composer Francesco Paolo Tosti and Rocco Siffredi. The town maintains international ties through sister-city agreements with Cassino, Italy; Volgograd, Russia; and Metković, Croatia. These partnerships often reflect the town's shared military history, particularly with Volgograd (formerly Stalingrad) and Cassino, which anchored the opposite end of the Gustav Line.