- Category : 1837-births
- Type : GE
- Profile : 2/5 - Hermit / Heretic
- Definition : Split - Small (29,34,57)
- Incarnation Cross : RAX Laws 1
Prussian military officer and military writer, and son of composer Friedrich Wilhelm Jähns.
In 1885 he was promoted to Lieutenant-Colonel and retired in 1886.
He died in Berlin on 19 September 1900, aged 63.