Sigismondo Pandolfo Malatesta (1417-1468) was an Italian condottiere, nobleman, and lord of Rimini. In 1433, he was knighted by the Holy Roman Emperor Sigismund, and in honor of this distinction he changed his name from the Italian Gismondo to Sigismondo. Born as the illegitimate son of Pandolfo Malatesta, he sought to secure his position amongst the other hereditary princes of the Italian states. He achieved this through military prowess as a condottiere, the commander of a free army. On March 18, 1435, he was named captain general of the Church, a distinction bestowed by Pope Eugenius IV and noted on the obverse of this medal.

Castel Sismondo, the subject of this medal, was an impressive castle-palace conceived by Sigismondo as a way of further securing his position within Rimini. The imposing fortress broadcast by this medal could have several meanings, including demonstrating Sigismondo's skill as a soldier and military engineer, as well as standing for the city of Rimini and the ruler's control over his domain. The first stone was laid on March 20, 1437, though construction would continue in various phases for some fifteen years.

The year 1446 was an important year for Sigismondo. It was in that year that he defeated Francesco Sforza at Gradara, the ceremonial inauguration of Castel Sismondo was held, and Sigismondo may have begun his notorious affair with Isotta degli Atti. While the inauguration of Castel Sismondo occurred in 1446, many different medals in addition to ones showing the castle, including pieces commemorating Isotta, contain that date, and it is generally accepted that the medals were created later. Based on excavation finds from the castle in 1624 and from the Tempio Malatestiano in 1948, a date of late 1450 to January 1451 has been proposed for this medal.

Several variants of this medal were created, with two major bust types. While this type shows Sigismondo in courtly dress, the other portrays him wearing armor. Sigismondo concealed a large quantity of medals within Castel Sismondo and other castles and buildings within his territory in order to perpetuate his name in conjunction with his most important building projects. While some medals contain the artist's name, medals needed for foundation deposits lack it. The various Castel Sismondo medals form one of the most famous types of early Renaissance medals, and were created in great numbers, surely achieving the goal of perpetuating the name of Sigimondo Pandolfo Malatesta through the ages. These medals are also significant in art history in that they were the first to feature an architectural design as the reverse subject.