It was in development for HBO until Amazon picked it up in 2014.
In the pilot episode, during a meeting with a Nazi doctor who leans on Monroe Stahr in regards to anti-German content, the executives mention studios who go along with the contract listing, among others, Warner Bros. In fact, Warner Bros. was the only studio to ignore this and jeopardized their major supporter of American produced movies.
Amazon Orginal. The pilot debuted in June 2016 and the show got a season order, debuting in July 2017.