According to several scholars, the origins of the name Desenzano on lake Garda can be found in the "Fundus Decentianus". In Roman times Desenzano del Garda probably extended along the hill lying between the castle and the lake garda. Its center was the "borgo regio", the location of the vast archeological site of the Roman villa, which developed between the era of the Roman Republic and the 5th century A.D. The court and large estate of Desenzano, which also had a church and a small fort, passed into the hands of the S. Zenone monks of Verona in 878. Emperor Henry II assigned the county to Bosone I in 1031. In 1170 Niceta introduced the Catharist heresy to this area. Desenzano del Garda even had a Catharist bishop named Giovanni il Bello [John the Fair]. Giovanni di Lugio, the great Catharist philosopher, was also from Desenzano.
In 1276 the Bishop of Verona quelled the Catharist movement by burning the heretics at the stake. Under Venetian rule, the town became an administrative center of great political and economic importance in 1426, The forage and grains grown on the plains were sold at its market. At the beginning of the 18th century, the town was pillaged several times during the War of the Spanish Succession. One of the decisive battles of the Second War of Independence was fought in the hamlet of S. Martino on June 24, 1859.

Standing against the last archway of Palazzo Todeschini (facing west), the stone bears the date MDLV. It served two purposes: it was a pedestal for the town criers in the square, and also a place on which bankrupt citizens were publicly smacked three times on their nude buttocks as punishment. According to Tullio Ferro, after the punishment the victims, still clutching their trousers in their hands, attempted to escape by running down Via Annunciata, which the people called "Bankrupt Road".

The monument, which is about 5 km from Desenzano on lake Garda, was built in memory of the bloody battle between the French-Piedmont and Austrian troops on June 24, 1859. There is an ossuary chapel with over a thousand skulls and bones of the 2,619 war victims, a museum with documents and relics from the Italian Risorgimento period and the Second War of Independence, and a tower almost 65 meters tall.
Topped with a panoramic terrace, the tower of San Martino della Battaglia was inaugurated in 1893 and dedicated to King Vittorio Emanuele II. The top can be reached by a ramp about 500 m. long. Opening onto the ramp are two galleries and seven frescoed rooms decorated with Risorgimento motifs.

Every first Sunday of the month, Piazza Malvezzi in Desenzano del Garda becomes a bustling place filled with booths displaying splendid antiques (paintings, silver, watches, jewelry, furniture, prints, books, postcards, etc.). The antiques market is a a special event for avid collectors and curious onlookers alike at lake Garda.