What were the major reasons why Europeans explorers went on great voyages 
of exploration in the 15th and 16th centuries?

A major reason behind these explorations was that the Ottoman Turks had blocked the
overland trade routes to Asia through their capture of Constantinople in 1453. Consequently,
not only did it become more dangerous to travel, but luxury items such as silk, spices, gold
and silver became extremely expensive. A new route by sea had to be found to India and
China and this resulted in European explorers searching for the Northwest Passage (see map).
Other reasons included:
 
Political reasons
Kings wanted more power. By creating colonies overseas they hoped they would become richer and more powerful. Colonies could also provide them with gold and silver.
 

 
Commercial reasons
Merchants hoped to get rich in return for paying to equip the voyage. If the ship
returned with spices, silk, and gold, the merchants could sell them for high prices.

Technological reasons
There were now better ships (caravels), improved maps and new navigational
instruments such as the astrolabe and the magnetic compass.

Religious reasons
Church leaders wanted to send missionaries to newly-discovered lands. They
wanted to convert the people of other lands to the Christian faith.

Do the following questions on Topic 1: Reasons for Exploration