Words related to himself

him (pron.)
Old English him, originally dative masculine and neuter of he, from Proto-Germanic *hi- (see he). Beginning 10c. it replaced hine as masculine accusative, a process completed by 15c. The dative roots of the -m ending are retained in German (ihm) and Dutch (hem). Hine persists, barely, as the southern England dialectal 'un, 'n for "him."
self (pron.)

Old English self, seolf, sylf "one's own person, -self; own, same," from Proto-Germanic *selbaz (source also of Old Norse sjalfr, Old Frisian self, Dutch zelf, Old High German selb, German selb, selbst, Gothic silba), Proto-Germanic *selbaz "self," from PIE *sel-bho-, suffixed form of root *s(w)e-, pronoun of the third person and reflexive (referring back to the subject of a sentence), also used in forms denoting the speaker's social group, "(we our-)selves" (see idiom).

Trying to define yourself is like trying to bite your own teeth. [attributed to Alan Watts, who did often use the image in this sense in his talks, if not in these exact words]

Its use in compounds to form reflexive pronouns grew out of independent use in Old English. As a noun from early 14c.

herself (pron.)
emphatic or reflexive form of third person feminine pronoun, Old English hire self; see her (objective case) + self. Originally dative, but since 14c. often treated as genitive, hence her own sweet self, etc. Also compare himself.
hisself (pron.)
c. 1400; a shift in felt meaning of the first element of himself (q.v.) from dative to genitive created this new word, but the same process did not change herself.