No, Haig worked in the Whitehouse for Reagan. I believe your might be thinking of Iran-Contra, when Col. Oliver North sabotaged the Intel community by claiming to have White House authority to (look it up in Wikipedia, I could explain it, because I knew North during that time but I don't really want to give you a detailed account for you to just say 'oh you're wrong). Gen. Haig was a a little bit of a peacock, no one hated him, just thought he was a little toooo precious. Haig is most famously remembered as the guy who announced he was in charge when Ronald Reagan was shot. It was a sour note because he was only chief of staff, not in the line of responsibility if Reagan had died, of course we still had George Bush (41) and if he had also died or been rendered unable to serve, the Speaker of the House would have become President. The only reason this became a clinker, was Haig was a retired General and should have known better.
Personally, I don't really think he was claiming to be heir to the throne, I think he meant to reassure the nation.....unfortunately, it was a major gaff. Ollie North was pardoned by President Bush because North knew where the bodies were buried and the Intel Community view him as a traitor.