late 14c., "one's lot or destiny; predetermined course of life;" also "one's guiding spirit," from Old French fate and directly from Latin fata (source also of Spanish hado, Portuguese fado, Italian fato), neuter plural of fatum "prophetic declaration of what must be, oracle, prediction," thus the Latin word's usual sense, "that which is ordained, destiny, fate," literally "thing spoken (by the gods)," from neuter past participle of fari "to speak," from PIE root *bha- (2) "to speak, tell, say."
From early 15c. as "power that rules destinies, agency which predetermines events; supernatural predetermination;" also "destiny personified." Meaning "that which must be" is from 1660s; sense of "final event" is from 1768. The Latin sense evolution is from "sentence of the Gods" (Greek theosphaton) to "lot, portion" (Greek moira, personified as a goddess in Homer). The sense "one of the three goddesses (Clotho, Lachesis, and Atropos) who determined the course of a human life" is in English by 1580s. Often in a bad sense in Latin: "bad luck, ill fortune; mishap, ruin; a pest or plague." The native word in English was wyrd (see weird).