The town was built at the end of the 16th century by the Knights of St John as the island’s new capital and, more importantly, as a fortress commanding an impregnable position over the peninsula. The city developed around what is now Republic Street, Old Bakery Street and Merchants Street, the latter containing some of the finest examples of Maltese-style Baroque architecture in the islands. The Co-Cathedral of St John has an austere exterior, but the interior is a sumptuous mixture of gilded tracery, marble mosaic floors and a lapis lazuli altar behind which is a remarkable marble group of the Baptism of Christ. The painting by Caravaggio of the beheading of St John is in the Oratory. The Grand Master’s Palace in Republic Street was built 500 years ago as the abode of the Grand Master of the Order of St John, and contains a series of paintings depicting the great siege of 1565, painted by a pupil of Michelangelo, and a group of tapestries originally designed for Louis XIV. The palace also houses an armory which has one of the best collections in existence. The Manoel Theater, named after one of the most popular Grand Masters, is the second-oldest theater in Europe and stages performances of opera, theater, music and ballet between October and May. The National Museum of Fine Art, housed in an 18th-century palace, has a collection of furniture, paintings and treasures connected with the Knights of St John. The Church of Our Lady of Victories, built in 1566, is the oldest church in Valletta and was built to commemorate the victory over the Turks. At the nearby Auberge de Provence is the National Museum of Archaeology, which has exhibits from the area dating back to prehistory. The town also has a bustling market in the Floriana suburb on Sunday mornings and another one in Merchants Street from Monday to Saturday.