BOOTS ON THE GROUND 2.0

ego(n.) by 1707, in metaphysics, "the self; that which feels, acts, or thinks," from Latin ego "I" (cognate with Old English ic; see I); its use is implied in egoity. They that have pleaded against Propriety, and would have all things common in this World, have forgotten that there is a Propriety, in our present Egoity, and Natural Constitution, which rendereth some accidental Propriety necessary to us (etc.) ["The Practical Works of the Late Reverend and Pious Mr. Richard Baxter," London, 1707] Psychoanalytic (Freudian) sense is from 1894; sense of "conceit" is by 1891. Ego-trip is attested by 1969, from trip (n.). Related: egoical. In the book of Egoism it is written, Possession without obligation to the object possessed approaches felicity. [George Meredith, "The Egoist," 1879] https://www.etymonline.com/word/ego

Pretty much same article on all agencies.