What are the key factors that led to the beginning of Renaissance?

The Renaissance was a period of scientific, intellectual,
and cultural awakening beginning in mid-14th century Italy.  The Renaissance stressed
humanist ideas, that is ideas founded in classical Greek and Roman thought, from
philosophy and education to art and cultural influence.
 

One key reason for the Renaissance was
the emergence of secular curiosity.  During the long feudal
period in Western Europe, education was done through the church.  Not even kings were
necessarily literate; those who could read and write [in most cases] learned through the
church.  This logically means that all education was non-secular; it was founded in
Catholic principles.  The Black Death, and a combination of other factors, led to the
decline of feudalism.  With increased trading with the East, new and different thoughts,
principles, and ideas came into Europe, and a renewed interest in secular education came
about.

Another reason for the Renaissance
was the printing press coupled
with humanism.  We have already defined humanism as a
revival of classical Greek and Roman thought and culture.  Humanism became a basis for
new works, paintings, sculptures, and texts.  These texts could now be widely
disseminated thanks to the printing press (a technology adapted from a wood-block press
invented in Tang/Song China in the 1000's CE).  The printing press allowed for fast
reproduction of text.  Because of this, single page pamphlets became the best ways to
share information.  This was crucial to Western European growth as a whole- instead of
waiting for cultures to independently develop new ideas and concepts, the information
could be shared as quickly as the pamphlet could be carried from merchant to merchant.
 

Another crucial reason that allowed for Renaissance was
the impact of the Black Death on Europe.  Carried over by
Mongols into trading ports on the Black and Caspian Sea, the Black Death arrived by
merchant ships to Sicily in 1347.  Within four years, thanks to a prevalence of plague
infected fleas and rats, plague had run its way through most of Europe (the areas that
are now known as Poland Belarus, Estonia, Latvia and Lithuania (among others) were not
affected), and up to 1/3 of the population is estimated to have died from plague.  This
impact the political situation in Europe because the plague knocked out an overwhelming
amount of peasants.  Because the feudal system in Europe relied heavily on the peasants
for food production, labor, and other services, a diminished labor force had major
consequences for production.  Those peasants that survived revolted against their
vassals (for they were doing more work for no greater reward) and eventually the feudal
system crumbled.  Peasants were granted land and money for their work; this made the
entire feudal system pointless.  A new political system was needed, and leaders sought
out different ideas for ruling their people.  This helped encourage learning and trade,
which both ushered in Renaissance.