Porta Maggiore could be called the “Gate of honour” (“Porta d'onore”) because it has been standing on the old Roman road Via Emilia that goes towards Romagna region and many sovereigns and popes passed under this gate. It was built with a keep in the second half of the 13th century and rebuilt again in the 14th and 15th centuries. Important construction works were carried out by the pope Julius II at the beginning of the 16th century: the new bigger fortress included the old keep and a new passage was opened on the North. Later, the gate was reopened again on the main axe of Via Emilia together with the construction of a new long bridge over the moat. The “portico” (arcades) leading to the church Santa Maria degli Alemanni was built outside of the gate at the beginning of the 17th century. The gate was rebuilt again by the architect Gian Giacomo Dotti in 1770. The destruction of the gate was decided in 1903 but demolition works were stopped in 1909 after a long and heated debate. Rudiments of the oldest construction were saved and restored by the Comitato per Bologna storico artistica (Committee of artistic and historical Bologna) under the direction of Alfonso Rubbiani.
Source: "Restauro delle porte di Bologna 2007-2009"