Æ

Æ is a grapheme formed from the letters a and e. Originally a ligature representing a Latin diphthong, it has been promoted to the full status of a letter in the alphabets of many languages. As a letter of the Old English alphabet, it was called æsc ‘ash tree' after the Anglo-Saxon Futhorc rune    which it transliterated; its traditional name in English is still ash (pronounced ).
See more at Wikipedia.org...