Is your boss a tyrant of Machiavellian proportions? If it makes you feel better, you're not alone. According to a study by the Employment Law Alliance, almost half of all employees have been targeted by a bully boss.

Do you have a boss who is off the wall - we're talking certifiably nuts? If it's any consolation, take comfort in knowing that you have more company than you can imagine. The simple truth is that bully or tyrant bosses can be found in abundance. Unfortunately, the majority can't legally be institutionalized. Many should not be bosses.

Tyrannical behaviour comes in all forms. There are bosses who are mind-controlling abusers, manic-depressive and psychotic. There are obnoxious bully bosses who rule by intimidation, insist on getting their way and fly off the handle easily. They treat subordinates like children and seldom ask for anyone's input. There are also predator bosses, a term that is explained in management consultant Harvey Hornstein's book, Brutal Bosses and Their Prey (Penguin Putnam), in which he defines two species of tyrannical bosses: "The Conqueror" and "The Manipulator".

Conqueror bosses prey on employees' weaknesses. They find great thrills in treating the workplace like a battlefield. Once they sense an employee's soft spot, they pounce on it. The unsuspecting victim doesn't stand a chance.

Manipulator bosses are the smoothest of bullies. They fear becoming less valued if their underlings get any recognition for exemplary work. Manipulator bosses are backstabbers who'll go to frightening lengths to look good to their superiors.