Answer:
There are two major landforms that are protecting India from invasion. The first one is a major water surface that surrounds India and the second one are large mountains on the North. Therefore it was hard to conquer this area, as it was physically well protected.
Step-by-step explanation:
Indian peninsula has a specific position and is therefore often called Indian subcontinent. Since the period of first civilization India was a land that was hard to conquer. Just take into account that even Alexander the Great wasn't able to subdue it due to geographical and climate problems.