Ordo domus Sanctæ Mariæ Theutonicorum Ierosolimitanorum is Latin for the ancient Teutonic German Knights. They began at the end of the 12th century as a Roman Catholic religious order and became a crusading militia in the Middle Ages bearing a black cross on their white tunics. Being the 'Order of the German House of St. Mary in Jerusalem', in the 19th century their commanders wore a black Maltese Cross around their necks, which was called the Marian Cross.
A Jewelled Cross used in Ave Maria devotions is sometimes referred to as a Marian Cross or Mater Cross, as is a crucifix which includes an image of the Virgin Mary, although this style may also be called a Unity Cross, symbolising the two-in-oneness of Jesus and Mary.
Any style of cross, with or without a corpus, and adorned with a letter 'M', of any proportion, might be referred to as a Marian Cross. The 'M' may be superimposed on the cross beam, or as in our example above, in the lower right quadrant. (See also the Calatrava Cross.)
The 'M' refers to Mary's station at the foot of the cross and symbolizes her vocation as Mater Dolorosa (Mother of Sorrows). Pope John Paul II, known as a very Marian pope, had a personal coat-of-arms with an 'M' beneath the right arm of the cross.
A much less ornately decorated Marian Cross is shown on the next page