Whilst St John’s houses some impressive independent works of art, like Caravaggio’s ‘The Beheading of Saint John the Baptist’, the decorative interior of the church is a work of art in itself.
Mattia Preti, the artist commissioned to carry out the 17th century decoration of the interior, was one of the most outstanding artists of the seicento. Starting with the vault, he depicted episodes from the life of St John the Baptist. With his perfect draughtsmanship and skilful use of colour, a masterpiece of illusionistic effects emerged. On designs prepared by Preti, the plain walls of the nave and chapels were carved with elaborate motifs characteristic of Baroque ornamentation transforming the walls into a riot of gilded foliage, flowers and angels.
A number of other renowned artists and sculptors contributed to the beautiful interior including Michelangelo Merisi da Caravaggio, Giuseppe Mazzuoli, Massimiliano Soldani Benzi, Polidoro da Caravaggio, Alessandro Algardi, Ciro Ferri and Matteo Perez d’Aleccio, as well as respected Maltese artists such as Stefano Erardi.
The museum is a treasure house in itself. It holds beautiful collections of sacred vestments, Flemish tapestries, a magnificent gilt bronze monstrance intended to hold the relic of the Baptist’s forearm, and an important collection of illuminated choral books as well as other objets d’art.