How do I clear history in Linux?

Hello all,

Please can anybody help me with a command to clear history of all the command I ever typed from command prompt in Linux. I share a system with a number of people that access the system with the same username. I wouldn’t want somebody to re-execute a command that I had already executed before either by mistake or intentionally.

I have tried using “man history” on mandrake 9.1 but did not give me any result. I also searched the web without success.

Thanks in advance