Short answers, pulled from the story.
On the 2nd of June 1998, Marvel Entertainment Group and Toy Biz merged to form a new corporate entity. This deal marked the end of an era for Ronald Perelman's ownership and the beginning of a fresh chapter for the company.
Carl Icahn stepped into the void by purchasing bonds at 20% of their face value in late 1996. He used these holdings to gain control over the company's stock and board of directors before winning court approval to replace Perelman's leadership team in February 1997.
Shareholders approved the deal on the 31st of December 2009, making it official that day after The Walt Disney Company announced its intention to acquire Marvel Entertainment for $4 billion on the 31st of August 2009. The transaction included all major divisions such as Marvel Studios, Marvel Comics, and licensing operations.
By the 29th of March 2023, Disney folded remaining units into other departments, ending Marvel Entertainment as an independent subsidiary. This dissolution marked the completion of over two decades of transformation from a struggling publisher to a global entertainment powerhouse.
Sony Pictures held the Spider-Man license while 20th Century Fox controlled X-Men and Fantastic Four properties for much of the late 1990s and early 2000s. This strategy allowed Marvel to generate revenue without bearing production costs or risks but meant losing control over how characters were portrayed on screen.