As the story goes, on his way up the WWWF ladder Bruno and Vince Sr had a falling out. Vince wanted Bruno in NY full time while Bruno didn't want to commit. This lead to Vince booking Bruno in two different cities on the same night, not telling Bruno about the second. Due to the "no show" Bruno was suspended by Athletic Commissions across the country, essentially blackballing him from wrestling for a period of time.

During that time, Bruno went to work in Toronto and turned into a huge draw there which brought Vince Sr crawling back, and the rest is history!

did not know this.

I had heard something like this, but wasn't sure of the details.