Definition of Heavyweight
The Heavyweight division in mixed martial arts consists of everybody that fights between the weights of 206 pounds and 265 pounds. Fighters can weigh in at one pound over 265 for a non-title fight, though the maximum for a title fight is 265 pounds.
The Heavyweight division has the greatest disparity in weight, from lowest allowable weight to highest allowable weight, of any of the divisions that are used by any of the major mixed martial arts promotions (UFC, Bellator, WSOF). The "superheavyweight" division is used by some smaller promotions.
The inaugural UFC Heavyweight champion was Mark Coleman. Coleman defeated Dan Severn at UFC 12 (February 7th, 1997) to claim the title, and ended up holding the title for a total of 170 days.
Since that time, a number of different names have held the UFC's Heavyweight title, including Randy Couture (multiple times), Josh Barnett, Frank Mir (multiple times), Tim Sylvia (multiple times), Brock Lesnar, Cain Velasquez (multiple times) and Junior dos Santos.
Thanks to the finishing power and incredible physiques of many Heavyweight fighters, the Heavyweight division (especially the UFC's Heavyweight division) produces some of the most memorable fights. After all, who can forget Brock Lesnar throwing a tantrum after defeating Frank Mir at UFC 100? Who can forget Junior dos Santos knocking out Cain Velasquez on the UFC's very first Fox event? Who can forget Randy Couture clubbing Tim Sylvia over the course of five rounds to regain the Heavyweight title?
One of the only drawbacks of the UFC's Heavyweight division is its lack of depth at the top. After all, Cain Velasquez has fought Junior dos Santos three times already, and there is a very strong likelihood that they will fight at least once more.