Furius Dionysius Filocalus or Filocalus was a Roman calligrapher and stone engraver, specialized in epigraphic texts, who was active in the second half of the fourth century.
One of his most noteworthy works is the "Chronography of 354", also known as the "Calendar of 354", of which the original has been lost. It is the oldest known Christian calendar, with the first known reference to the celebration of the Christmas, although it also incorporates Roman festivities. The most complete copy conserved today is a manuscript of the 17th century which is kept in the Barberini collection. This is the reproduction of a "Codex Luxemburgensis" of the Carolingian dynasty, which was lost in the seventeenth century.
The "chronography" was commissioned by a wealthy Roman Christian, known as Valentinus, to whom it was dedicated. The original manuscript miniatures were also probably the work of Filocalus.
Filocalus was the official engraver of Pope Damasus (304 - 384), and described himself as "Damasi pappae cultor atque amator" ("admirer and personal friend of Pope Damasus"). The archaeologist Giovanni Battista de Rossi suggests that his inscriptions were reserved for the cult of the martyrs. It is not known for certain whether these inscriptions were drawn and engraved by Filocalus, or only drawn by him, but the first hypothesis seems to be correct. The precision of the cut of the stone and the organic regularity between the letters suggest the work of a master who works based on a sketch, rather than a craftsman copying an elaborate drawing.
For these inscriptions, called the Epigrammata Damasiana, Filocalus created an original letterform that is known as filocalian letter or philocalian script. Its main features are its thin and wavy ornamental serifs. It also has a strong contrast, with thin horizontal strokes and with vertical strokes which are thick in the downward direction and thin in the ascendant. It also presents vertically squashed forms; especially in the letters C, D, G, H, M, N, O, Q, R and T, which are wider than they are tall. The rounded letters (D, G, O, Q) all have an oblique axis.