Answer:
He did not want anyone having anywhere near as much power as he had
Explanation:
The answer is: The sea
Back then, the techology that exist to travel by sea was not as developed as it is today. If an empire decided to travel through the sea in order to do some conquests, that empire will risk several things, such as:
- Loss in directions
- The ships could be swallowed by harsh wheather in the middle of the sea
- It need a lot of resources to maintain the armies during the travel
