The painting is the central panel of the altarpiece of Saint Peter Martyr from the Convent of Santo Tomás in Avila, together with four other panels in the Museum (P611, 614). The three altarpieces installed in the chancel of Santo Tomás in Ávila had a similar composition: a central panel with the image of the titular saint flanked by four lateral panels, two on either side, depicting episodes from their lives that emphasise each saint’s supernatural powers and their defence of Christian orthodoxy.

For the creation of the cycles of images in the altarpieces for the monastery of Santo Tomás in Ávila, Tomás de Torquemada probably gave Pedro de Berruguete access to an illuminated manuscript of legends of the Dominican saints of the type owned by many of the Order’s communities. It would have provided the starting point for altarpieces in which the painter, following the authoritarian monk’s instructions, introduced various iconographic modifications intended to give these hagiographic cycles an inquisitorial significance.

The saint is identified by the knife in his head and the tip of the bloodstained dagger sticking out of his chest, the palm with three crowns and the open book showing the first words of the Creed.