The first volcano erupted approximately 4.5 billion years ago. This is when the earth first came into existence, and long before the first humans walked the earth, according to Scholastic, Inc.
The most catastrophic volcanic eruption in modern times took place in 1815. A volcano named Tambora erupted in Indonesia, causing the death of approximately 90,000 people, though most of them died from starvation rather than as a direct result of the eruption.
When a volcano has an intense, explosive eruption, it can fling rocks at a velocity of up to 670 miles per hour. Generally speaking, when a volcano starts to erupt, the eruption continues for around 10 years. Some eruptions have been known to last for hundreds of years.