Around the twelfth century, simple grave markers began to appear as did elaborate effigies. this was as part of increasing emphasis on

The correct answer to this question is that:

There was an increasing emphasis on our "Individualism".

Let us note that individualism is a moral or social principle which gives human independence and identity great importance. The presence of markers on our graves signifies that until death or until the time we are beneath the ground, our self-identity would remain intact