Venice is the extreme "tail wagging the dog" situation. Venice is dinky. It's not much bigger than San Francisco. Yet it was a major European power for centuries.
Venice was small by land mass, but controlled the Eastern Mediterranean, and therefore the Black Sea endpoint of the Silk Road, which was immensely profitable.
Consequently, Vasco da Gama rounding Africa in 1498 doomed Venice as a great power.
Consequently, Vasco da Gama rounding Africa in 1498 doomed Venice as a great power.
(All from memory, 100% factuality not guaranteed)