Betta fish is extremely agressive

Question
Hello. I have a red betta splenden named Jorge. :-) He is incredibly agressive and I recently had to remove him from my community tank. I have never had problems keeping betta with gourami or any other type of fish. However, this particular fish is probably the most agressive betta fish I have ever seen. Also something important I should probably mention. I have had this betta for almost 3 years and he has never shown this much agression towards any type of fish including gourami and has always been kept in a community tank. What do you think could be causing this agression all of a sudden?

Answer
How big is the tank that you had to remove the betta from? Where there any fish that were recently added to the tank (within the past month or so)? You can email me @ LstFllnANGL@gmail.com with the answers. Based on the information that you've given me - it just seems like your betta decided one day not to like his tank mates (=D). I'll give a more in-depth answer once I know some more details.