The aesthetic goth originated from the goth subculture, which spread from British club scenes in the early 1980s into mainstream awareness in the 1990s. The scene was named after the genre of music they coalesced around, gothic rock. Goth rock began as a post-punk subgenre of British rock in the late 1970s. Contemporary writers described it as “positive punk” or “punk gothique”, due to one of the genre’s main influences being gothic fiction.
Gothic fiction describes the popular British fiction style that peaked in the 1790s, but was popular for 40 years in either direction. It’s characterized being set in the medieval period and evoking strong emotions, particularly fear and awe. Mary Shelley’s Frankenstein is a canonical example. As you might suspect at this point, gothic horror literature is named after gothic architecture. Specifically, the feelings of “medieval” and “barbaric” the era evoked.
Gothic architecture refers to two different movements: the Gothic Revival movement prevalent in early 1800s England, and the original movement it sought to emulate, the European style of medieval castles and cathedrals from roughly 1200-1500. Like Baroque architecture, the movement was named by its replacement. So their names emphasize their perceived negative qualities. Baroque there meaning needlessly complicated, and gothic here meaning barbaric and uncivilized. Contemporaries instead referred to gothic architecture as “modern work”, “French style”, or “German style”.
Gothic came to mean barbaric or uncivilized around the year 300 by association with the Goths, a group of Germanic people who were driven from their homeland in what is now Ukraine by the Huns, to Roman lands. As such, most of their modern characterization is limited to “eastern barbarians who sacked Rome as it fell”. Sadly, this is where our trail goes cold. It is unclear what the Goths were named for. There’s some suggestive gesturing at the island of Gotland south of Sweden, but nothing concrete.