Columbus was an Italian. He believed the world was round, though few people knew or believed it at that time. He thought if he always went west, he would at last get to India. His friend, Isabella, the queen of Spain, gave him support which made it possible for him to start his journey.
On August 3, 1492, Columbus started from Spain with three small ships. He and his men stepped into what was then an unknown sea. Many thought that they would never come back. On and on they went with their ships, not knowing where they were going!
For a long time there was nothing but wide waters all around them. Day after day, and night after night passed by. The men who were with him became scared, and tried to force him to return. But Columbus was brave and would not turn back. At last, a land appeared.
When the people of the island saw Columbus's ships, they were very surprised. They had never heard of Europe or the people who lived there. Columbus and his men filled their ships with fruits, vegetables, plants and animals. He even took some island people with him as he returned to Spain.
When the other countries of Europe heard of the great discovery of a new world, they wanted to share in its riches. So many things like bananas, sugar and cotton were brought into Europe from there. And these things changed Europe a lot.
The potato plant which was taken back to Europe also changed Europe. As it grew easily in Europe, it meant more food for the people there and so the population of Europe increase.