This cross is central to a larger piece, the Benedict Medal, which is dedicated to the piety and devotion in honour of St. Benedict of Nursia (Spanish and Latin: San Benito) who died in 547. Since then, 16 popes have been called Benedict, including the current Pontiff.
St. Benedict Medal
On one side of the medal is an image of St. Benedict, where he holds a cross (crozier or 'rod of discipline') in his right hand and the Regula monachorum ('Rule for Monasteries') in his left hand.
The image is encircled with the inscription Eius in obitu nostro praesentia muniamur! (May we be strengthened by his presence in the hour of our death!) The words 'his presence' refers to St. Benedict, a patron saint of dying people. Benedict himself cheated death, at least once, when jealous monks conspired to kill him by lacing his drink with poison. Whilst blessing the cup with the sign of the cross, it miraculously shattered. A broken cup is often shown on medals to symbolise this. He succumbed to natural death in the year 547.
On the other side of the medal is a looped Fleurie Cross. In the four quarters of the cross we see the letters 'C S P B', the acronym of Crux Sancti Patris Benedicti (the Cross of our holy father Benedict).
The cross itself contains the letters 'C S S M L' on the vertical arm, and 'N D S M D' on the horizontal arm. The cross is encircled with the letters 'V R S N S M V S M Q L I V B'.
The meaning behind these letters were forgotten and remained a mystery for hundreds of years, until 1647, when a manuscript of the Gospels, written in 1415 was found in the Abbey of Metten (Bavaria, Germany). The manuscript contained a pen picture of Saint Benedict holding a cross in one hand and a scroll in the other. Both these items were inscribed with a prayer used when making use of the sign of the cross against temptations: Vade Retro Satana, Nunquam Suade Mihi Vana - Sunt Mala Quae Libas, Ipse Venena Bibas. 'Be gone, Satan! Do not suggest to me thy vanities - evil are the things thou profferest, drink thou thy own poison.' The initial letters of these words form the acronym surrounding the cross on the medal.
On the medal cross, the letters are the acronym for Crux Sacra Sit Mihi Lux (May the Holy Cross be my light) inscribed on the vertical arm, and Non Draco Sit Mihi Dux (Let not the dragon be my guide), on the horizontal arm.