KRS-One began his recording career as one third of the hip hop group Boogie Down Productions, or BDP, alongside DJ Scott La Rock and Derrick "D-Nice" Jones. After being rejected by radio DJs Mr. Magic and Marley Marl, KRS-One went on to diss the two and those associated with them, sparking what was later known as The Bridge Wars. Additionally, KRS-One had taken offense to "The Bridge", a song by Marley Marl's protege, MC Shan (KRS-One later reconciled with Marley Marl, producing an album with him in 2007 titled Hip Hop Lives). The song could be interpreted as a claim that Queensbridge was the monument of hip-hop, though MC Shan has repeatedly denied this claim. Still, KRS-One "dissed" the song with the BDP record "South Bronx." A second round of volleys ensued with Shan's "Kill That Noise" and BDP's "The Bridge Is Over." KRS-One, demonstrating his nickname "The Blastmaster", gave a live performance against MC Shan, and many conceded he had won the battle. Many believe this live performance to be the first MC battle where rappers attack each other, instead of a battle between who can get the crowd more hyped.
On April 29, 2007, KRS-One again defended his statements on the September 11 attacks when asked about them during an appearance on Hannity's America on the Fox News network. He stated that he meant that people cheered that the establishment had taken a hit, not that people were dying or had died. He also discussed, among other things, the Don Imus scandal and the use of profanity in hip-hop.
KRS-One's step-son (Randy Parker) was found dead in his Atlanta, Georgia, apartment on July 6, 2007. The Medical Examiner's office stated that Parker had died of a gunshot wound to the head, and listed the cause of death as suicide.