King Philippe (II, III) of Spain managed to buy 20 years of European peace with his Treaty of London that divided up North America into zones of influence and settlement.
That was just about the longest 20 years they'd had since maybe 400 BC.
Still didn't prevent more action against the Ottomans, but that was OUTSIDE the primary zone of European intrigue and combat.
The American and Russian occupation of much of Europe since 1945 has created the longest peacetime period ever known there.