Venice Monopoly -- the "Age of Discovery"

Since at least the Venetian conquest of Constantinople in 1204, Venetian dominance of mediterranean trade was extreme enough to warrant a continual search, by every other European monarch, for alternative routes. When the Ottomans captured Constatinople in 1453, the Venetians and the Ottomans were by far the largest players in the Meditteranean, and the pressure for alternative routes increased. Spain & Portugal, indulging in muslim ethnic cleansing at the time, were particularly keen to not deal with the Ottomans.

Many other forces were involved, including the European monarchs' need to conquer, to maintain growth & power. But the strategic position of Venice led, more or less directly, to the European invasion of the New World.