The Celts (usually pronounced pron.: /ˈkɛlts/ but sometimes /ˈsɛlts/, see pronunciation of Celtic) or Kelts were an ethno-linguistic group of tribal societies in Iron Age and Medieval Europe who spoke Celtic languages and had a similar culture, although the relationship between the ethnic, linguistic and cultural elements remains uncertain and controversial.
A cross is a geometrical figure consisting of two lines or bars perpendicular to each other, dividing one or two of the lines in half. The lines usually run vertically and horizontally; if they run obliquely, the design is technically termed a saltire, although the arms of a saltire need not meet at right angles.
The cross is one of the most ancient human symbols, and has been used by many religions, most notably Christianity. It is frequently a representation of the division of the world into four elements (Chevalier, 1997) or cardinal points, or alternately as the union of the concepts of divinity, the vertical line, and the world, the horizontal line (Koch, 1955).