https://www.cnet.com/news/star-wars-spinoff-the-mandalorian-will-be-released-at-launch-of-disney-plus/

A short featurette about The Mandalorian, shown to investors gathered at the Disney studio lot, featured the Mandalorian bounty-hunter character walking across a gray, snowy landscape near an alien outpost. He holds out a beeping tracker with a blinking red light, and the scene cuts to the character entering a bar with drums pounding. 

In the featurette, Favreau said the series starts with the bounty-hunting Mandalorian tracking down quarries. "This is a character you've never met before and period of time you've never seen before," Favreau says. The story takes place five years after the events of Return of the Jedi.