Mina Gregori's inspired attribution of the Palazzo Pitti s portrait of a Knight of Malta (Figs. l and 4) to Caravaggio in 1966 has borne fruit in a widespread, if not quite universal, acceptance of it as a masterpiece of the artist's last years. ' But whether it was executed in Malta during Caravaggio's protracted sojourn there from 12th/14thJuly 1607 to September/October 1608, or in Sicily or Naples (where the Knights of the Order of St John of Jerusalem had priories and commanderies) or at another date during his last four wanderjahre, has not been clear. Technical and colouristic parallels point most forcefully towards Malta or the immediately following year in Sicily, but this does not exclude the possibility that it was painted during one of the two enveloping Neapolitan phases (1606-07 and 1609- 10).

ON 1st December 1608, some two months after his escape from a Maltese prison and flight to Sicily, Fra Michelangelo da Caravaggio was defrocked in absentia by his fellow brothers of the Order of St John of Jerusalem, the Knights of Malta.' Stripped of the honorary knighthood 'd'Obbedienza Magistrale' that the Grand Master Alof de Wignacourt had granted him on 14th July, the artist had now greatly diminished his chances of receiving a papal pardon for the homicide he had committed in Rome in 1606. The knights' tribunal performed the privatio habitas in the recently constructed Oratory of S. Giovanni Decollato in the Conventual Church of St John in Valletta. Thus the absent painter suffered the indignity of being degraded directly in front of his freshly completed masterpiece, the Beheading of St John the Baptist (Fig. 7). t At the conclusion of the trial, as the court minutes state, Caravaggio was 'expelled and thrust forth' from the order 'like a rotten and fetid limb'.

In his 'Vita di Armanno' Passeri records that Herman van Swanevelt executed landscape friezes in many noble Roman palaces, going on to say that these were in fresco with tempera additions a secco. The only mural paintings he specifies, however, are the two lunettes in the sacristy of S. Maria sopra Nfinerva, of which one survives (Fig. l 9), painted while the artist was confined in the monastery there for failing to observe a fast. l Until now this lunette has been the sole fresco associated with Swanevelt. The purpose of this article is to propose the attribution to him of a frieze with scenes from the life ofJoseph in the east sving of the Palazzo Pamphilj in Piazza Navona, Rome, the authorship of which has not hitherto been satisfactorily resolved despite some scholarly debate during the decade following the Brazilian government's acquisition of the palace in 1960.9

This article arises from one by Richard Spear published in the September 1994 issue of this Magazine, in which he proposes that Guido Reni's superb painting of St Jerome with an angel in the Detroit Institute of Arts (Fig.34) could, notwithstanding the discrepancy in subject, be identical with a St Matthew begun by Reni (who died on 18th August 1642) and then finished by Guercino, in whose account book a receipt of forty scudi is recorded for such a work on 2nd January 1643.1 In raising what he takes to be a potential question of artistic authorship, Spear's article serves the useful purpose of opening to further investigation a problem touched upon by Stephen Pepper in an article concerning the Detroit painting published in 1969. ' For there are a number of facts which, in the opinions of the present authors, militate against Spearns proposal and which entail investigating the documentary evidence relating to it in fuller detail.