As it relates to war

1. Does the green sentence mean:

a) The Altar of Zeus is one of the last important artworks about art in the story of pre-Christian art

or

b) The Altar of Zeus is one of the last important artworks in the story of pre-Christian art because it is about art.

2. Does the yellow sentence mean "The Altar of Zeus is one of the artworks that enjoys such a property (affects the art of next two millennia)?

3. Does the red "First" imply "The first reason for the influence of this altar on the rat forms of the next two millennia is that..."?

Context:

The Altar of Zeus and Athena, Pergamon is a remarkable concluding masterpiece in the story of pre-Christian art as it relates to war. But the art forms developed before Christ reverberate through the next two millennia and dominate their forms. This remarkable altarpiece in effect lays this groundwork. First, by making it the most impressive structure in the acropolis, the king rendered war and its successful conduct the measure of his society and of public concern.