We first meet Zorba in Fantastic Four #198, written by Marv Wolfman and illustrated by Keith Pollard and Joe Sinnott.
Reed gets shot down as he's trying to invade Doom's Latverian castle.
Reed knocks the guards out and lowers the drawbridge.
Reed stretches himself so he looks like Hauptmann and tries sneaking up on Doom, but Doom realizes who he is and knocks him out.
Meanwhile, Reed escapes and manages to free the rest of the Four.
And in #200... The cover is by Jack Kirby.
Later, one of Doom's guards tells him that Zorba is leading a revolt.
The Fantastic Four escape, and Reed stops the machine creating the whirlwinds.
Ben finds Alicia (who Doom was having work on his statue).
Reed goes after Doom, while the rest of the Four fly to the UN.
Doom locks Reed into his "Murder Room," with various deathtraps.
Doom receives the signal and goes to activate the solartron, leaving Reed alone.
Reed attacks Doom, placing a device on his armor that short-circuits it. Doom tries reaching the controls of the solartron...
The U.N. delegates start to attack the three.
Meanwhile, Reed breaks free from the ice.
Say my name, bitch!
Reed stops the device, freeing the delegates from Doom's control.
Doom and Zorba's story continues in Fantastic Four Annual #15. It's written by Doug Moench and illustrated by Tom Sutton.
Hauptmann arrives and tells them that Zorba discovered that Doom is missing, and that the operation must be performed that night.
Borgo and his men go to retrieve Doom's armor, which Hauptmann needs to revive Doom.
Zorba goes to check on the armor, but the place is gassed by Borgo's men.
Hauptmann starts to get ready for the final phase of the operation.
Then, in John Byrne's Fantastic Four #246...
And the story concludes in Fantastic Four #247.
A woman runs out of her home, crying "Kristoff! No! Not Kristoff! Do not kill my son!"
The Fantastic Four are shocked to see the woman's reaction. Sue asks Reed if they've made a terrible mistake, but the Thing thinks it's a set-up.
Kristoff's mother tells how Doom was ousted and replaced with Zorba.
Doom and the Fantastic Four destroy the robots. Then more villagers arrive.
Inside a tavern, which the the Thing notices used be the headquarters of the Latverian resistance, Doom tells one of the villagers to "put the woman's body someplace safe. I swear I shall see Zorba pay for her murder."
As the killer robots flood the streets, Doom and the four fight them off. After they're gone, the Thing notices Doom is gone.
Doom returns to the Fantastic Four and tells them that Zorba is no longer the king of Latveria, and that the crown is his. He tells the team to leave, warning them that the next time they meet he will destroy them.
And we see Doom dealing with the aftermath of Zorba's reign in Fantastic Four #258.