What is meant by "Eurocentric approach to history" in Guns, Germs and Steel?

For Diamond, the Eurocentric approach to history is one
whereby history is told from the European point of view.  This gives much in way of
credibility and legitimacy to the European conquest of the world during the Age of
Exploration.  It is also reflective of the narrative that allows and excuses the actions
of the European nations in their hopes for conquest and triumph.  A Euro centric
approach to history does not entirely validate the narratives of those who were
oppressed by the Europeans.  It also tends to discredit the idea that Europeans' success
was predicated upon enslavement and death of indigenous opposition to their efforts.  It
glorifies European and Western approaches to telling the narrative of history.  It is
this "preeminence" of European culture that defines Eurocentric approaches to history. 
In this vein, Diamond's work serves to operate on two levels.  The first is to unmask
this Eurocentric approach, something that has been embedded in so much of historical
narratives about the Age of Exploration.  Additionally, Diamond's work seeks to explore
how history can be told in a manner whereby historical reality can be told in a
dialectically materialist vein and not one where "preeminence" of European culture is
such a large part.