The first estate was made up of the religious leaders who were in charge of the Church. While these individuals made up only 1% of the total population, they controlled almost 10% of the land in France. This land brought them a great deal of wealth from the products produced on it and in the form of rent from peasants.
Those who belonged to this estate also received a tithing, or tax of 10% of all the earnings of those who lived on their land. This tithing was supposed to be utilized to run the Church. However, it was often used to fund the extravagant lifestyles of those who belonged to the first estate.
I do not know everything, still many things I understand.
Johann Wolfgang von Goethe
Slaves in Ancient Rome made up to 40% of the population.