who directed it?
Joss Whedon
The Avengers (2012 film)
Written and directed by Joss Whedon, it features an ensemble cast including Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, and Jeremy Renner as the Avengers, alongside Tom Hiddleston, Clark Gregg, Cobie Smulders, Stellan Skarsgård, and Samuel L. Jackson. 
who are the original avengers in the movies Tony Stark, Steve Rogers, Bruce Banner, and Thor.
wiki:6372326
The Avengers (2012 film) [SEP] Introduction
It grossed over $1.5 billion worldwide, setting numerous box office records and becoming the third-highest-grossing film of all time as well as the highest-grossing film of 2012. It is the first Marvel production to generate $1 billion in ticket sales. In 2017, "The Avengers" was featured as one of the 100 greatest films of all time in an "Empire" magazine poll. Three sequels have been released: "" (2015), "" (2018), and "" (2019).