St. John's Co-Cathedral is a Catholic cathedral located in Valletta, Malta. It was built between 1573 and 1577 by the Knights of the Order of Saint John of Jerusalem according to the plans of the Maltese military architect Ġlormu Cassar (then already at the origin of several important buildings in Valletta).

Funded and commissioned in 1572 by Jean de La Cassière, the Order's grandmaster, he made it the conventual church of the knights and a co-cathedral, a title conferred by Pius VII in 18161, since it shares this title with the Saint Cathedral. -Pierre-et-Saint-Paul de Mdina.


It was built by the architect Ġlormu Cassar from 1573 to 1577 and decorated by Mattia Preti from 1662 to 1667.

Interior of the Co-Cathedral.

The floor, all in marble, is completely made up of cenotaphs, where 405 knights2 of the Order of Saint John of Jerusalem are represented. There is also a crypt that contains the tombs of great masters, including Philippe de Villiers de L'Isle-Adam, Claude de La Sengle, Jean de Valette, and Alof de Wignacourt.


There are eight chapels, and each normally represents a hospitable language. The chapels are the chapel of Germany or the Three Kings, that of Italy or of St. Catherine, of France or of St. Paul, of Provence or of St. Michael including the Anglo-Bavarian chapel or of the Relics, the Chapel of the Blessed Sacrament, Auvergne or Saint-Sébastien, Aragon or Saint-George and de Castille or Saint-Jacques.

The location of four other chapels are, in fact, reserved for entrances. At the end of the nave, the entrance to the sacristy, opposite the oratory entrance. Formerly (1603-1604), the residences of the grand prior and that of the vice-prior. Between the chapels of Germany and Italy, the side entrance to the co-cathedral, in front of it, the entrance to the old conventual cemetery, today of the museum.


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The Beheading of Saint John the Baptist: a painting by Caravaggio painted in 1608. The painting was commissioned by the Grand Master of the Order of Saint John of Jerusalem to be placed as an altarpiece in the oratory of Saint John, a chapel of the Order's novices.

An inscription near the side entrance, from which the Hospitallers entered, recalls the brevity of the terrestrial peregrination: 'You who walk on the dead, remember that one day they will walk on you'.