Ideological: The thirst for adventures,fame and wealth/The veracity of the humanists.
Political: Increase in the power of the kings.
Economical:New trade routes that brought supplies of spices from asia.
Scientific:They thought that the earth smaller and round and more geographical knowledge.
Tecnhiques: New technical instruments such as the astrolabe cartography /new vessels:the carrack and caravel.Religious:The fight against the the infidels/Extension of christianity.
The portuguese explorations:Portugals aim was to gain acces to sudans gold supplies and trade with india.There were problems between Portugal and castilla so they sign the treaty of alcacovas in 1749.
Discovery of America(1492):America was discovered by Christopher Columbus, a sailor who may have been born in Genoa.
His aim based on conviction that the world was round was to sail westwards across the atlantic to reach India.(Capitulation of santa fe)
Sharing out the world and new expeditions:The Catholic Monarchs were granted sovereignty over the indies by the pope,and,to avoid conflict with the portuguese crown,they agreed the areas of influence of their respective countries in the treaty of tordesillas(1494).Then in 1519 and 1522 Magellan and elcano completed the first voyage.