Martin of Tours served in the imperial cavalry during the reign of Constantine the Great, stationed near Amiens in Gaul. According to the legend, he encountered a shivering beggar at the city gates one winter day and cut his cloak in half with his sword, giving one portion to the man^[1]. Tradition holds that Christ later appeared to Martin in a dream and told him that what he had done for the beggar, he had done for Christ himself, the revelation that gives the episode its full theological weight beyond a simple act of kindness^[1].

The subject was chosen for the chapel's lateral altarpiece specifically because Martin was the namesake and patron saint of Martin Ramirez, the chapel's founder, and because the saint's act of charity suited a donor known for his own charitable works^[2]. The choice also fit a broader current in Spanish religious art of the period: after the Council of Trent, the Catholic Church placed charity and other good works at the centre of its theology of salvation, in direct contrast to Protestant teaching, and pictures illustrating the virtue of charity were common in Spanish painting from the late sixteenth into the mid-seventeenth century^[2].

El Greco painted Martin not in the dress of fourth-century Gaul but in gold-damascened armour and a ruff typical of fashionable Toledan clothing of his own day, an anachronism that collapsed the distance between the fourth-century legend and El Greco's own sixteenth-century Toledo, suggesting the timelessness of its lesson in the same way he had done in his Burial of the Count of Orgaz^[2]. The saint appears astride a white Arabian horse, seen from a low vantage point that makes both figures loom monumentally over the landscape below, his naturalistic proportions set deliberately against the beggar's attenuated, almost nude body, whose obvious distortion gives him an unworldly appearance that anticipates the revelation still to come in Martin's dream^[1].