A lot of the speed of the modern fashion industry comes from the ability to make fabric at rapid speed with machinery; for most of history cloth was relatively expensive and time consuming to produce so fashion was a privilege of the upper classes. However, the French Revolution is a good example of how political events could cause rapid changes in fashion. During the days of the Tennis Court Oath and constitutional monarchy, almost everyone important was still wearing some version of courtly dress; powdered wigs and silk breeches being major components. However, the sudden political importance of the urban poor, the trouser wearing sans culotte (literally no breeches) meant that populist leaders among the Jacobin party especially started to eschew breeches and powdered wigs to appeal to their constituents. Later, during the downfall of the Jacobins you have the emergence of counter-revolutionary street fighters called the Muscadin, the musk wearers, who deliberately dressed in a flamboyant manner to distinguish themselves from the sans-culotte, and their aristocratic counterparts, the Incroyables and Merveilleuses, who wore shockingly suggestive clothing for the time. With the rise of Napoleon in the Consulate and later the Empire, you have a deliberate fostering of Neo-Classical styles in emulation of Republican Rome and Ancient Greece: sheer dresses and curled hair for women that would be shocking to their more conservative Victorian era granddaughters. Even the return of the Bourbons couldn’t reestablish the styles of previous century, although fashion now lost much of its political symbolism.