"a procession, a train of persons on horseback or in carriages," 1640s, via French cavalcade (15c.), from Italian cavalcata, from cavalcare "to ride on horseback," from Vulgar Latin *caballicare (also source of Spanish cabalgada, Portuguese cavalgata), from Latin caballus (see cavalier (n.)).
Literally, "a procession on horseback;" general sense of "a procession" of any sort is from 1660s; in 20c. -cade came to be regarded as a suffix and rode off on its own to form motorcade (1909), etc. The word's earliest use in English was in the now-obsolete sense "a horseback ride" (1590s).