SOURCE: Germanic */h/
OE /h/ had three different realizations, or allophones, depending upon its phonetic environment.
1. Voiceless velar fricative--initially before vowels and the consonants /l/, /r/, /n/, and /w/. Example: hand "hand."
2. Voiceless palatal fricative--after front vowels. Example: riht "right."
3. Voiceless velar fricative, but more forcefully articulated than (1) above--like ch in Modern German ach. This allophone occurred in environments that did not call for (1) or (2) above. Example: þurh "through."
The REFLEX for all three of these allophones was ME /h/ .