Topic summary
Typographic ligature

Extracted from the Wikipedia article Ligature (writing).
Æ and Œ
The character ⟨Æ⟩ (lower case ⟨æ⟩; in ancient times named æsc) when used in Danish, Norwegian, Icelandic, or Old English is not a typographic ligature. It is a distinct letter — a vowel — and when collated, may be given a different place in the alphabetical order than Ae.