“Since 1450 there have been six major world reserve currency periods. Portugal (1450–1530), Spain (1530–1640), Netherlands (1640–1720), France (1720–1815), Great Britain (1815–1920), and the United States from 1921 to today. If you notice the average currency span is 94 years. The US dollar presently has been the world’s reserve currency for roughly 99 years.”

https://www.midasgoldgroup.com/news/world-reserve-currencies-since-1450/