Answer by taking a quote from the following article:

Iron Man is a fictional superhero appearing in American comic books published by Marvel Comics. The character was created by writer and editor Stan Lee, developed by scripter Larry Lieber, and designed by artists Don Heck and Jack Kirby. The character made his first appearance in Tales of Suspense #39 (cover dated March 1963). A wealthy American business magnate, playboy, and ingenious scientist, Anthony Edward "Tony" Stark suffers a severe chest injury during a kidnapping in which his captors attempt to force him to build a weapon of mass destruction.

After issue #99 (March 1968), the Tales of Suspense series was renamed Captain America. An Iron Man story appeared in the one-shot comic Iron Man and Sub-Mariner (April 1968), before the "Golden Avenger" made his solo debut with Iron Man #1 (May 1968). The series' indicia gives its copyright title Iron Man, while the trademarked cover logo of most issues is The Invincible Iron Man. Artist George Tuska began a decade long association with the character with Iron Man #5 (Sept. 1968). Writer Mike Friedrich and artist Jim Starlin's brief collaboration on the Iron Man series introduced Mentor, Starfox, and Thanos in issue #55 (Feb. 1973). Friedrich scripted a metafictional story in which Iron Man visited the San Diego Comic Convention and met several Marvel Comics writers and artists. He then wrote the multi-issue "War of the Super-Villains" storyline which ran through 1975.  Writer David Michelinie, co-plotter/inker Bob Layton, and penciler John Romita Jr. became the creative team on the series with Iron Man #116 (Nov. 1978). Micheline and Layton established Tony Stark's alcoholism with the story "Demon in a Bottle", and introduced several supporting characters, including Stark's bodyguard girlfriend Bethany Cabe; Stark's personal pilot and confidant James Rhodes, who later became the superhero War Machine; and rival industrialist Justin Hammer, who was revealed to be the employer of numerous high-tech armed enemies Iron Man fought over the years. The duo also introduced the concept of Stark's specialized armors as he acquired a dangerous vendetta with Doctor Doom. The team worked together through #154 (Jan. 1982), with Michelinie writing three issues without Layton.  Following Michelinie and Layton's departures, Dennis O'Neil became the new writer of the series and had Stark relapse into alcoholism. Much of O'Neil's work on this plot thread was based on experiences with alcoholics he knew personally. Jim Rhodes replaced Stark as Iron Man in issue #169 (April 1983) and wore the armor for the next two years of stories. O'Neil returned Tony Stark to the Iron Man role in issue #200 (Nov. 1985). Michelinie and Layton became the creative team once again in issue #215 (Feb. 1987). They crafted the "Armor Wars" storyline beginning in #225 (Dec. 1987) through #231 (June 1988). John Byrne and John Romita Jr. produced a sequel titled "Armor Wars II" in issues #258 (July 1990) to #266 (March 1991). The series had a crossover with the other Avengers related titles as part of the "Operation: Galactic Storm" storyline.

What kind of crossover?
Operation: Galactic Storm"