Maria Theresa defied expectations of what a female ruler could achieve in the 18th century. When she ascended the throne of the Habsburg empire in 1740, there were riots on the streets of Vienna, and Europe's major powers prepared to pounce. Yet, as Pieter Judson tells Spencer Mizen, over the next four decades Maria Theresa introduced wide-ranging social reforms, and turned Austria into a military force to be reckoned with. The HistoryExtra podcast is produced by the team behind BBC History Magazine. Learn more about your ad choices. Visit podcastchoices.com/adchoices