Short answers, pulled from the story.
Walt Disney Studios Motion Pictures began operations on the 10th of November 1953 after Walt Disney and his brother Roy O. Disney formed the Buena Vista Film Distribution Company following RKO Pictures refusal to distribute The Living Desert.
The organization dropped the word Film from its official title in April 1960 and became known as Buena Vista Pictures Distribution Inc. by late July 1990 before Disney officially discontinued the use of the Buena Vista brand for distribution purposes on the 25th of April 2007.
Disney entered an estimated thirty-film agreement over five years with DreamWorks in early 2009 that expired in August 2016 after Universal Pictures replaced Disney as distributor.
Plans emerged to purchase 21st Century Fox which included 20th Century Fox assets by the 14th of December 2017 and the acquisition completed on the 20th of March 2019 allowing Disney to distribute 20th Century Studios films domestically.
Italia Film became Disney's exclusive theatrical partner for Middle East and North Africa markets since 1993 while Era Communications handled distribution in Taiwan from 1992 to 1995 before Buena Vista took over local operations.