Baring-Gould’s sources: Modern Roman Martyrology. The name of Longinus was not known to the Greeks previous to the patriarch Germanus, in 715. It was introduced amongst the Westerns from the Apocryphal Gospel of Nicodemus. There is no reliable authority for the Acts and martyrdom of this saint.

The name Longinus, given in the gospel of Nicodemus to the soldier who pierced the side of Christ, is probably due to a mistake. The name is probably Latinized from Longche , a spear. Some think that the soldier who pierced the side, and the centurion who exclaimed at the earthquake, confessing the Sonship of Christ, are the same, but there is the greatest uncertainty on every point connected with Longinus. The Greeks commemorate Longinus the Centurion on October 16th. The Latin Acts of S. Longinus confuse the centurion and the soldier together. The Greek Acts pretend to be by S. Hesychius (March 28th), but are an impudent forgery of late date. It is pretended that the body of S. Longinus was found at Mantua in 1304, together with the sponge stained with Christ's blood, wherewith he had assisted in cleansing our Lord's body when it was taken down from the cross. These relics [the bodily remains of a saint, or objects they used, kept with honor] have been distributed in various places. Part are in Prague, others in Carlstein, the body in the Vatican at Rome. But the Sardinians assert that they possess the body of S. Longinus, which was found in their island, where he had suffered under Nero. And the Greeks say he suffered in Gabala, in Cappadocia [a region of central Turkey]. The head is, however, also said to have been found in Jerusalem, and carried into Cappadocia.