Did Iron Man start the Avengers?
No, actually It was Nick fury to propose an idea to create a team of superheroes to fight and the fight against non earthling which wants to harm earth which is later named as avenger.
Captain America was the first Avenger created by an experiment conducted by mr. stark(father of Tony stark). Which you can see in the first part of Captain America series that is Captain America: The first Avenger.
Yep. Iron man was the first avenger. However avengers are a group of superhumans which is ordined by a top secret service member (active or former). So according to mcu avengers have been assembled before too. And i dunn recall the guy who created it back then but the first avenger innit back then was zarda.! According to comics. Btw the answer to your question is hellll naaaawwww....
Did he start them no, but did he help to assemble, pay, motivate, and inspire people to join yes.
Technically yes, but it all started back with the experiment(leander deeny) resulting Captain America ,i.e steve Rogers.
Dr. Erskine ,the name of the experimenting scientist . But the technology was under the supervision of tony Starks father, Howard Stark.
If you are asking if the man known as Tony Stark started the Avengers then no, although he had a big role in their selection and assembly it was Nick Fury as director of S.H.I.E.L.D in opposition to the wishes of the World Security Council. Also it is worth noting that it was Captain America which first inspired the concept of the avengers.
If you are asking if the film Iron Man started the avengers then yes it was the first film in which the concept of the avengers is teased.
No, according to the avengers movie timeline it is Jack fury who started avengers when Loki attacked earth