Sense of "property left by will, a gift by will" appeared in Scottish mid-15c. Legacy-hunter is attested from 1690s. French legs "a legacy" is a bad spelling of Old French lais (see lease (n.)). French legacie is attested only from 16c.
mid-14c., patrimoine, "property of the Church," also "spiritual legacy of Christ," from Old French patremoine "heritage, patrimony" (12c.) and directly from Latin patrimonium "a paternal estate, inheritance from a father," also figurative, from pater (genitive patris) "father" (see father (n.)) + -monium, suffix signifying action, state, condition.
In English law, the meaning "right or property inherited from a father or ancestors" is attested from late 14c. Figurative sense of "immaterial things handed down from the past, heritage" is from 1580s. A curious sense contrast to matrimony.
1530s, "inheritance, succession," from French hérédité, from Old French eredite "inheritance, legacy" (12c.), from Latin hereditatem (nominative hereditas) "heirship, inheritance, an inheritance, condition of being an heir," from heres (genitive heredis) "heir, heiress" (from PIE root *ghe- "to be empty, left behind," source also of Greek khēra "widow"). Legal sense of "inheritable quality or character" first recorded 1784; the modern biological sense "transmission of qualities from parents to offspring" seems to be found first in 1863, introduced by Herbert Spencer.
Old English becweðan "to say, speak to, exhort, blame," also "leave by will;" from be- + cweðan "to say," from Proto-Germanic *kwithan (see quoth). The simple verb became obsolete, but its old, strong past tense survived through Middle English as quoth.
The original sense of "say, utter" died out 13c., leaving the word with only the legal sense of "transfer by legacy." Compare bequest. "An old word kept alive in wills" [OED 1st ed.]. Old English bequeðere meant "interpreter, translator." Related: Bequeathed; bequeathing.