Shawn Carter, aka Jay-Z, released his debut Reasonable Doubt in June 1996. He had known The Notorious B.I.G. since their Brooklyn youth, and the two rap together on the album’s Brooklyn’s Finest, where Biggie throws in a line about the rumours surrounding Tupac and his wife Faith Evans. In Tupac’s eyes, that put Jay-Z on the other side.
Tupac’s response
In the summer of 1996 Tupac recorded a string of songs at Death Row lashing out at Bad Boy and its circle, and Jay-Z was among the names he dropped, for example on Bomb First (My Second Reply), the intro to the Makaveli album released in November 1996. In 2020 Murder Inc. co-founder Irv Gotti named Brooklyn’s Finest as the trigger: Tupac feared Jay-Z would get drawn into his feud with Biggie. All Out is often cited as well, but it only came out in 2001 on the posthumous album Until the End of Time. Jay-Z did not respond publicly while Tupac was alive. According to DJ Clark Kent, he recorded a reply but, out of respect, did not release it after Tupac’s death and performed it live only once.
Jay-Z is said to have later told Vibe that he didn’t take the attacks seriously because Tupac was dissing anyone connected to Biggie at the time, but that he had been a fan since the Digital Underground days. That quote survives only second-hand.
What came after
After Biggie’s death in 1997 Jay-Z laid claim to the title “King of New York.” That led to his famous feud with Nas from 2001, which had nothing to do with Tupac any more.
In 2002 Jay-Z released ‘03 Bonnie & Clyde with Beyoncé, built on Tupac’s Me and My Girlfriend from the Makaveli album. Some saw this as hypocritical; it can also be read as a belated tribute. In November 2003, at his farewell concert at Madison Square Garden, Jay-Z brought Afeni Shakur and Biggie’s mother Voletta Wallace on stage together, an image many saw as a symbolic end to the East-West hostility.
It is also often claimed that Jay-Z “started” the feud and that many of his lines matched Biggie’s or Tupac’s. Both are opinions, not documented facts. The bigger picture is on the East vs. West page.