Thin Ogham Bar Ring: Ogham is the earliest form of writing in Ireland. It dates to around the 4th century A.D. – some believe earlier – and was in use for around 500 years. This alphabet is made up of a series of strokes, either along or across a line. It was carved on standing stones to commemorate someone, using the edge of the stone as the centre line. They normally read from bottom to top, or left to right.