As a conjunction, "previous to the time when," from c. 1200. Contrasting before and after in illustrations is from Hogarth (1768). Before the mast in old sailing ship jargon in reference to the life of a common sailor is from the place of their berths, in front of the fore-mast.
Early 14c. as a preposition, "before in time," and as a conjunction, "earlier than the time when, before." Once the literary equivalent of before, it now has been replaced by that word except in nautical use, colloquial dialects, and in combinations such as aforesaid, aforethought.
Now displaced by before. In nautical use, "toward the bows of the ship." Merged from 13c. with the abbreviated forms of afore and before and thus formerly often written 'fore. As a noun, "the front," from 1630s. The warning cry in golf is first recorded 1878, probably a contraction of before.
Beneath was the usual word; below was very rare in Middle English and gained currency only in 16c. It is frequent in Shakespeare. As a preposition from 1570s. In nautical use, "off-duty," in contradistinction to "on deck." Meaning "inferior in rank or dignity" is from c. 1600. According to Fowler, below is the opposite of above and concerns difference of level and suggests comparison of independent things. Under is the opposite of over and is concerned with superposition and subjection and suggests some interrelation.
early 15c., preceden, "lead the way; occur or exist before, go before in order of time," from Old French preceder and directly from Latin praecedere "to go before," from prae "before" (see pre-) + cedere "to go" (from PIE root *ked- "to go, yield"). Meaning "to walk in front of" is late 15c.; that of "to go before in rank or importance" is attested from mid-15c. Related: Preceded; preceding.