Lay groundwork

1. Does "This remarkable altarpiece in effect lays this groundwork" mean "This alter piece enjoys such property, that is affects also the art of the next two millennia"?

2. What does "the measure of his society and of public concern" mean? Does it mean "a sign of his society that it will be known for and something that the public will always concern for"?

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. Second, by so closely allying his victorious troops with their gods, he also sanctified battle, thus making war and religion inseparable. Third, in artistic terms, by electing to depict the battle comprehensively at the moment of victory (success, failure, death, and dismemberment are all present), the sculptural programme paves the way for the battle paintings and depictions of war on canvas that are the hallmark of the next two millennia.