The quick answer people give me is: Breaking into such a fort is an uphill task. So it’s easier to defend a hill fort.
But there are a few things I still don’t get…
I’m assuming that forts are built to protect the population which lives around them (ie, outside them), not to protect what’s inside the fort. That way, wouldn’t it take more time for the garrison to exit the fort, descend all the way to the surrounding countryside, and protect the people? While the enemy, attacking from the plains would be much swifter, and could start the plunder of the countryside, before the defenders got there. I mean, don’t you want the police close by, when the robbers come?
Another point… the enemy would find besieging a hill fort easier than besieging a fort on flat land. A hill fort has a few well-defined pathways leading out (the rest would be steep cliffs), and these can be easily identified and blockaded by the enemy. Narrow hill paths could even be blown up, making it impossible for horses/elephants and foot soldiers to make their way down. Escape would be difficult, and food supply could be completely shut. But enforcing a complete blockade for a flat-land fort is much tougher. It would need to be completely surrounded on all sides, by a continuous ring of soldiers… possible only for a very big army, considering that some forts have perimeters several miles long.
Even during peace time, a hill fort would be quite a bother. Imagine the daily difficulty of hauling up food, firewood, construction material from the bazaars in the countryside. Communication with the outside would be slower. In the Sahyadri hills in Western India, where many hill forts are, monsoon winds are punishing… incessant, cold, wet and gale-force. Keeping the garrison motivated in such conditions would be a harder challenge on a hill fort.
But then, they did show a marked preference for hill forts. So what am I missing?
I’ve decided not to Google for an answer. Instead, I’m thinking… I’ll wait for someone to read this engage in lively debate with me.