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Years ago, Joe and Anthony Russo (known as the Russo brothers), would have seemed like an unlikely duo to direct a "Captain America" movie, let alone the biggest superhero movie in history: "Avengers: Infinity War."

But the duo did just that, and the crown jewel of the Marvel Cinematic Universe comes to theaters on April 27.

The pair started their career on the film festival circuit, and struggled to finance their first independent, low-budget film, called "Pieces." Swimming in debt, they were eventually called by filmmaker and producer Steven Soderbergh, who had seen "Pieces" at the Slamdance Film Festival and wanted to produce their next film.

From there, the brothers would mostly take on TV projects, primarily sitcoms such as "Arrested Development," "Happy Endings," and "Community."

Now, the Russos are ready to deliver the most anticipated superhero film of all time - and certainly one of the most ambitious crossover events ever - which could very well smash box office records.

Needless to say, it's an unusual career.

Here's a closer look at the career of the Russo Brothers: