
Saint Januarius, Bishop of Benevento and patron of Naples, was beheaded near Pozzuoli about AD 305. The executioner stands behind the saint and an angel descends with a palm of martyrdom.
The painting is presumably the modello for the large altarpiece in S. Spirito dei Napoletani, Rome, commissioned by Cardinal Tommaso Ruffo,which is likely either to precede or follow closely Giordano's Spanish period (1692 - 1702).