The Byzantine Emperor Nikephoros attacked and sacked the Bulgarian capital of Pliska, despite a proposal for peace from the Bulgarian Khan Krum. Krum watched from the Madara plateau as Nikephoros celebrated and burned Pliska, causing Krum's heart to cry and his tears to drip into the cave. In retaliation, Krum gathered his troops and ambushed Nikephoros' army in the mountains, killing Nikephoros. Krum had Nikephoros' skull covered in silver and, according to Bulgarian custom, drank wine from it with his soldiers.