My car died?

I needed a new waterpump after briefly overheating one day due to a leak. That was in the Fall. Over the Winter, I drove my truck, and started the MB like one time, drove it around the block and put it back in the garage, with it getting hot but not in the "red". Now I think my battery is dead. Is this common? It wioll go through the glow plug cycle, but it wont crank the motor. I guess I'm kind of worried that my motor has siezed up. Is this a possibility? I'll try to jump it today. I need to turn it around in the garage to work on it.