I want to delete my whatsapp history from my stolen device. How can I do that?
Unfortunetly, WhatsApp does not have a remote delete function that I know of. If you really want to get rid of the history, you can wipe your device remotely if you have anti-theft installed. I recommend trying Android Device Manager. It is most likely already activated on your phone. You can wipe it from there (If Android Device Manager has permissions to), or at least lock you phone and set a new device unlock code. I would always reccomend using Google's Find your Phone page, which is linked below. It will lead you through the different steps you can take to deal with a lost phone, and links to Android Device Manager.
Well, yes there's no remote functions for WhatsApp. But you can do this, Block the old sim and take a new sim with the same number and install and setup WhatsApp in another phone. This will prevent your old device from accessing your WhatsApp. Also you can use Android Device Manager to remotely wipe or lock the device. Hope you'll be safe from misusing of your lost phone and sim.