By Max Miedinger with art direction by Eduard Hoffmann at Haas. Design began in 1956 and first shown as Neue Haas Grotesk in 1957. Revised at Stempel and released for the Linotype as Helvetica in 1959. [Kupferschmid]
Revised at Linotype in 1982 as Neue Helvetica (more systematic) and again at Monotype in 2019 as Helvetica Now (3 size-specific subfamilies). See also Neue Haas Grotesk (Font Bureau/Linotype, 2012), a restoration of the original in two size-specific subfamilies.
Helvetica in use