Tossignano stands on a gypsum hill straddling the Santerno Valley, in a strategically dominant position that has made it, throughout time, an object of contention.

The Santerno valley has been inhabited since very ancient times. During prehistory, in the Paleolithic and Neolithic periods, hunters and explorers made their appearance in the valley, attracted by the fauna, the gathering of wild fruits, and the large forests. The first stable settlements in the valley date back to 2500 BC. Under the ruins of the Tossignano fortress, there is still a cave that has provided evidence of ancient human settlements. Inside, chipped flint and bones of eaten animals have been found. The Iron Age civilization left numerous testimonies, and Tossignano is considered one of the most important centers of the Villanovan culture in the Imola area. In the 4th century BC, the territory of Tossignano, like the entire Santerno valley, saw the invasions of Gallic populations. In the 3rd century BC, the Romans arrived in our territory. Tossignano, after the occupation of the Gauls, experienced Roman occupation. An ancient selenite quarry almost at the top of the village is still a witness to that period today. Despite this, the toponymy is attributed to the Umbrian populations who passed through and occupied the Apennines. The toponym Tuskum (place of worship) would have given rise to Tuscum oppidum, and Tossignano would originate from there. Tossignano, under the Romans, surpassed all the settlements of the Santerno valley in importance. In 456 AD, Tossignano is cited in several documents. In the 6th century AD, during the Byzantine rule, the Pieve of Santa Maria Assunta was erected in Tossignano, the oldest in the Santerno Valley. Even under the Byzantines, Tossignano remained the reference village of the valley. From castrum to pieve to commune. Tossignano crosses the centuries. With the death of Charlemagne (814 AD), a conflict opened that would span several centuries between the papacy and the Archbishop of Ravenna. Tossignano straddled the valley as well as the papacy and the archbishopric of Ravenna. In a period of crisis and calamity, a Tossignanese had the honor of ascending first to the chair of Sant'Apollinare in Ravenna and then to that of Peter in Rome. He would go down in history with the name of Pope John X from Tossignano, the one who defeated the Saracens on the Garigliano river. Tossignano was always a borderland. Thus Tossignano passed from Ravenna to Faenza then to Imola, multiple passages until the Concordat of Worms in 1122. It was around this period that Tossignano became a commune, and with this regency, it entered the struggles between Guelphs and Ghibellines, taking the side of the former, alongside Bologna. It was the Bolognese who erected the Palazzo Pretorio in the village. The 14th century saw Tossignano contested between the Bolognese and the Imolese. In this period, it was granted to the Alidosi family, who held the village until 1424. It was the most populous and rich settlement in the Santerno Valley. The Alidosi were followed by several other families. The Manfredi, the Sforza. From 1500 to 1503, the lord of Tossignano was Cesare Borgia, known as il Valentino. For a two-year period, the Venetians also governed Tossignano (1503-1505). Even the Carafa of Naples held the village for a very short period. The longest rule was from 1565 to 1700 with the Altemps, who gave Tossignano the form we see today. It was under their government that in 1622 what is today known as the Polenta Festival was established, to alleviate the suffering of the Tossignanese in a period of famine. Then other lords. In 1859, with the newborn Kingdom of Italy, Tossignano became part of the Province of Ravenna until 1884. From that year, it became part of the Province of Bologna, a historical ally. Tossignano would live peacefully until 1944 when, in the midst of World War II, it became the fulcrum of the German defensive line. The Allied armies struck the village repeatedly, trying to weaken the German resistance. On the night between April 11 and 12, 1945, Tossignano was liberated by the Italian troops of the Nembo. The village, except for the church of San Girolamo, was in ruins. Rubble everywhere, so much so that it was defined as "the Romagna Cassino". Over 90% of the village had been destroyed. In 1954, the municipal seat was moved to the village that had sprung up at the foot of Tossignano. Not only the seat but also the name of the municipality were changed. The Municipality of Tossignano gave way to the Municipality of Borgo Tossignano, despite having been almost entirely rebuilt. Of the village that dominated the Santerno Valley, which gave a pontiff to the Church, two blesseds and a venerable, and a multitude of professors to the University of Bologna, the remains of the fortress located on the top of the village and little more remain. Its name still resounds in the corridors of the Vatican inside the Gallery of Maps, where the village shows itself off in all its medieval splendor.