English terms with diacritical marks
The Old English Latin alphabet began to replace the Runic alphabet in the 9th century, due to the influence of Celtic Christian missionaries to the Anglo-Saxon kingdoms. The orthography of Old English – which was entirely handwritten in its own time – was not well standardized, though it did not use all the Latin letters, and included several letters not present in the modern alphabet. When reprinted (on a printing press or computer) in modern times, an overdot is occasionally used with two Latin letters to differentiate sounds for the reader:
Ogham
A variation is that the alphabet was first invented, for whatever reason, in 4th-century Irish settlements in west Wales after contact and intermarriage with Romanised Britons with a knowledge of the Latin alphabet. In fact, several ogham stones in Wales are bilingual, containing both Irish and British Latin, testifying to the international contacts that led to the existence of some of these stones.