Driving on a smooth-but-narrow paved road through a vast, moss-covered, lava-flow landscape, our guide explained, “This lava flow is 1,000 years old. We call it the Lava of Christianity because it hit the same year we became Christian.” Living on an island of live volcanos in the middle of the ocean is not always easy. Iceland has weathered an eruption every four or five years for at least a thousand years. With the eruption of 1783—one of the biggest lava flows in recorded history—the population dropped from 50,000 to 38,000. The eruption of the Eyjafjallajökull volcano in 2010 stopped air travel across Europe, inconveniencing a lot of travelers. But the 1783 Laki eruption had a bigger impact and literally helped change history. Its volcanic dust impacted weather and crops in Europe for several summers, causing widespread hunger. Some historians say those conditions contributed to the economic unrest that led to the French Revolution at the end of that decade.