First things first, I think we can all acknowledge that "corpse paint" in the vein of black metal is properly understood to refer to a particular style of facial makeup, that being the type that is deliberately intended to resemble a decaying human body, although allowances are often made for other overtly "evil" intentions such as "war" paint or demonic representation. This article is meant neither to insist on any dogmatic interpretation nor to dilute the significance of corpse paint's evolution in black metal, but merely to acknowledge that the tradition didn't spring full cloth out of nowhere.
Certainly the cultural tradition of face painting predates written history, both for ceremonial religious reasons as well as military ones. An entire volume could be written documenting these traditions, but for our purposes we can content ourselves with its evolution within the bounds of rock and roll.
"Shock rock" is typically agreed to have been ushered in by the success of Screamin' Jay Hawkins, best known for the immortal hit "I Put a Spell on You". Hawkins did not originate the use of face paint in the nascent genre, although his use of horror-related props and voodoo imagery were influential in bring a morbid predilection to rock and roll. His acolyte, Screaming Lord Sutch, was himself an irregular face paint wearer, but did similarly employ horrific imagery – albeit of a tongue-in-cheek variety – as on his 1963 single "Jack the Ripper".
Probably the most direct antecedent to what would later define the black metal look was England's Arthur Brown, who helped to bridge the gap between shock rock and acid rock in the mid-to-late 60's along with a flamboyant sense of theatricality that made frequent use of tribal masks and black-and-white face paint.
In terms of almost unintentionally evil-looking imagery, Brown even managed to one-up his immediate successor, the biggest of all shock rockers, one Alice Cooper. Alice Cooper actually started as a garage rock band before eventually segueing into a sort of proto-metal in the 70's – Cooper never really committed to a particular sound until his decidedly metal resurgence in the mid-80's – but the garish face paint, on stage beheadings and grand guignol vibe were part of his entertainment package from the earliest days.
Heavily influenced by the glam rock sense of showmanship, but eschewing its pop-leaning musical trappings for a beefier rock and roll sound, KISS brought a gringo-ized Japanese Kabuki look to the table, with bassist Gene Simmons' "demon" character exhibiting the most evil look face paint the genre had seen to that point. Simmons' look was allegedly a major inspiration on King Diamond, with his lascivious tongue wagging and blood spitting furthering the increasingly over-the-top horror vibe slowly infecting the genre.
While punk rather than metal, New Jersey's Misfits favored a 50's horror/sci-fi aesthetic that included a stylized greaser take on the ghoul look. Their mascot, the Crimson Ghost, helped enamor legions of listeners to the death-obsessed imagery of songs such as "Astro Zombies" and "Death Comes Ripping". Metal or not, the band has had an immense influence on the genre over the past 30+ years.
The most influential presence in metal face paint history, King Diamond apparently began dabbling in it back in his early days with Black Rose in the late 1970's, although I can't seem to locate any photographic evidence to effect. Either way, though, I don't think anyone disputes his preeminence in setting the bar during his time with Mercyful Fate, who released their first EP in 1982, a year before the thrash explosion that later paved the way for the first wave of black metal bands.
Prior to tidying up their sound a bit and re-emerging as Celtic Frost, Thomas Gabriel Warrior sported a primitive version of corpse paint in predecessors, Hellhammer. Although seriously lacking the decorative sophistication of King Diamond or even Alice Cooper, Gabriel insists to this day that the minimalism wasn't due to lack of creativity but a deliberate choice meant to invoke the undead. Which brings us to…
Arguably the single most important figure in all of black metal history even though he was around to see very little of it, the legacy of Per "Dead" Olin looms like a god over the genre. Ostensibly the first man to deliberately utilize face paint to simulate a photo-realistic corpse look rather than an ornamental or cosmetic pattern, Dead furthered the conceit by burying his clothes for days on end in the musty earth to give them a disinterred corpse look.
According to his bandmates and other friends in the scene, there was an otherworldly quality about Dead that seemed disconnected from the mortal coil. He was reported to be distant, immensely aloof and just generally hard to get close to. On April 8th, 1991 Per Olin took his life in violent fashion, slashing his wrists before taking off the top of his own head with a shotgun. Legends abound about his housemate and fellow Mayhem musician Euronymous finding the body and using pieces of his brain to make a ghoulish goulash as well as fashioning skull fragments into a makeshift necklace. An image of the crime scene was later used for the cover of bootleg Dawn of the Black Hearts (NSFW). These legends and offstage mystique – as much as Mayhem's music itself – helped to solidify the band as a major aesthetic influence on what came to be known as the Second Wave of Black Metal.
Dead's departure opened the door for Øystein "Euronymous" Aarseth to take center stage in the burgeoning movement. Euronymous had actually been in the band far longer than Dead, even, having co-founded the group back in 1984 with Manheim and Necrobutcher (Dead joined later in 1988). Shortly after Dead's suicide Euronymous opened Helvete, an underground record shop in Oslo. This record shop would serve as a unifying location for contemporary and future black metallers from Emperor, Thorns and Burzum. Euronymous continued Dead's tradition of simple-yet-evocative corpse paint imagery until his murder by Burzum's Varg "Count Grishnackh" Vikernes in August 1993.
From here things splinter exponentially with the explosive growth of Norwegian black metal in the early 1990's. More bands than not seem to have adopted Mayhem's corpse paint look, with the visual appeal soon becoming prominently featured on many black metal album covers, such as Darkthrone's A Blaze in the Northern Sky.
Finally, bands like Immortal took the colorless, black-and-white look of corpse paint and, combining it with old school metal outfit staples like bullet belts and long spikes, developed a sort of "war metal" look distinct from the purely functional makeup used by other early black metal progenitors.
… and since those halcyon days of the early 90's the style has continued evolving, with some bands adhering closely to the original, realistic corpse look and others looking to put their own stamp on it, the latter of which often leads the wearer further and further down a path of differentiation that can sometimes be indistinguishable for actual cooptation, as in this photo shoot of Rob Zombie's recent band.
See related coverage from previous annual installments of Black Metal History Month:
An Animated History of Corpse Paint (a sort of precursor to this article with stylized animated artwork and music clips in place of historical overview)
A Brief History of Corpse Paint (while seemingly no longer for sale, this amazing poster art offers an even more comprehensive visual guide to painted artists than the above)