What is the period in the 1500's when europeans started searching they did not know is called?

The Age of Exploration?

Correct! The period in the 1500s when Europeans started searching for new trade routes and territories that they were not aware of is known as the Age of Exploration.

To arrive at this answer, you can follow a few steps:

1. Understand the context of the question: The question asks for the period in the 1500s when Europeans started searching for unknown territories.
2. Analyze the options: The Age of Exploration is a well-known historical period that aligns with the context of the question.
3. Confirm the answer: By confirming that the Age of Exploration is indeed the right answer, you can cross-reference with additional information or resources if needed.

By following these steps, you can arrive at the correct answer and also understand the reasoning behind it.