line of walls and a castle were built by Charles V (who was also Holy Roman Emperor), in the first part of the 16th century. In 1656, a plague broke out in the city, killing a thousand inhabitants. In 1943, fighter aircraft based in Lecce helped support isolated Italian garrisons in the Aegean Sea during World War 2. Because they were delayed by the Allies, they couldn't prevent a defeat. In 1944 and 1945, B-24 long-range bombers of the 98th Heavy Bomber Group attached to the 15th U.S. Army Air Force were based in Lecce, from where the crews flew missions over Italy, the Balkans, Austria, Germany and France. Main sights Churches and religious buildings Church of the Holy Cross: Construction of the Chiesa di Santa Croce) was begun in 1353, but work halted until 1549, and it was completed only by 1695. The church has a richly decorated façade with animals, grotesque figures and vegetables, and a large rose window. Next to the church is the Government Palace, a former convent. Lecce Cathedral: The church was originally built in 1144, rebuilt in 1230, then totally restored in the 1659–70 by Giuseppe Zimbalo, who also built the five storey high bell tower, with an octagonal loggia. San Niccolò and Cataldo: The church is an example of Italo-Norman architecture. It was founded by Tancred of Sicily in 1180. In 1716 the façade was rebuilt, with the addition of numerous statues, but maintaining the original Romanesque portal. The walls were frescoed during the 15th-17th centuries. Celestine Convent: Built (1549–1695) in Baroque-style by Giuseppe Zimbalo. The courtyard was designed by Gabriele Riccardi. Santa Irene: This church was commissioned in 1591 by the Theatines and dedicated to Saint Irene. The architect was Francesco Grimaldi). It has a large façade showing different styles in the upper and lower parts. Above the portal stands a statue of Ste Irene (1717) by Mauro Manieri. The interior is on the Latin cross plan and is rather sober. The main altarpiece is a copy of the St Michael the Archangel by Guido Reni. The high altar has a Transport of the Holy Ark by Oronzo Tiso. In the right transept is one of the largest altars in Lecce, dedicated to Saint Cajetan (1651). Nearby is the Rococo altar of Saint Andrew Avellino. Also from the mid-17th century is the Altar of St Orontius by Francesco Antonio Zimbalo, followed by