Black departed from De Dannan in 1986, and 1987 saw the release of her first multi-platinum Irish album, "By the Time it Gets Dark". However, her popularity reached new heights with the release of the ground-breaking album, "No Frontiers", in August 1989. It rocketed to the top of the Irish album charts (it stayed in the Top 30 for over a year), and achieved triple-platinum status. Mary's popularity grew in the United States, due to several tours and widespread radio exposure.