According to the historians Cassiodorus and Jordanes in the beginning of 200 A.D. The Roman Empire was attacked by a Germanic tribe from southern Scandinavia. A century later it split into 2 tribes, Ostrogoth meaning “eastern Goth” and Visigoth meaning “western Goth.” In 370 A.D. both were attacked by Huns. The Ostrogoths merged with them and the Visigoths fled from them to a Roman province called Thrace and revolted killing the Roman Army and Emperor Valens at Adrianople present day Edirne, Turkey in 378 A.D. During the early 400’s they invaded Italy under there King Alaric and sacked Rome in 410. The Ostrogoths freed themselves of the Huns in 454 and conquered Italy in 488 under their king Theodric the Great. Both Gothic tribes were then reunited under him in 507. The Visigoths then moved to Gaul/France and to Spain and their empire there lasted into 711. The Ostrgoth’s empire lasted to 553.
They were feared because captives were sacrificed to their war god Tyz, and because of this the name Goth became associated with bad behavior and violence. In medieval and modern day Spain, Visigoths were thought to be the origin of Spanish nobility and in Latin America is used as a racial term referring to the Spaniards who oppressed the Native Americans. The Goths were actually the first Germanic people to convert to Christianity and in the 12th century religious buildings, castles and graveyards were built in Gothic architecture which has led to a time period called the Gothic era. In the 19th century Gothic literature first appeared because the stories took place in such places and lead it to represent dark stories of horror. In the late 20th century it came to represent a style and sound of darkness leading to a misconception of what a goth truly is.
You don't call a French person German, and the same goes for calling a person who's not of gothic ancestry a goth.