Indian rulers is Ashoka (304–232 BCE) of the Maurya Dynasty, who under the influence of Buddhism (rather than Brahmanism) came to regret his conquests in the Kalinga War. He vowed to end his empire, and eventually the entire political system collapsed. Muslim states Certain Muslim states developed the practice of making imported slaves as the ruling class, as with the Mamluks of Egypt and the Janissaries of the Ottoman empire, a process which started around the 8th century. Since these ruling class slaves were neither beholden to family nor to any tribe, but dependent only on the state, it ensured their loyalty towards the state. A later example would be the 16th-century Ottoman Empire practice of seeking out intelligent Christian children for high civil service or military positions, who were cut off from their family for their training. Europe In 11th-century Europe, instead of the state having the upper hand as in China, or the Brahmins having the upper hand as in India, there was a power conflict between state and church, the Investiture Controversy between Pope Gregory VII and Henry IV, Holy Roman Emperor. The papal party started to search for sources of law to strengthen its case for the universal jurisdiction of the church. They rediscovered the Justinian Code, the Corpus Iuris Civilis, in a library near Bologna in northern Italy in 1072, leading later to the student body called a "universitas", first in Bologna, and soon after in Paris, Oxford, Heidelberg, Cracow, and Copenhagen studying the code and displacing particularistic Salic law. The laws gave the Gregory the authority to excommunicate Henry IV, who was forced to walk to Canossa from Germany to Italy, stand barefoot in the snow for three days outside Canossa and to ask forgiveness from the pope on his knees. The Concordat of Worms ended the struggle between popes and emperors in 1122. It created balance between royal power and religious tradition not seen anywhere else before. Catholic leaders became accountable to the clergy and to the pope, who historically frequently objected to violence and wars, just as their counterparts in India had done, but in Europe the clergy did not weaken the states as much as Brahmins had done in India. The papal intercessions against wars between Catholic countries also led to the survival of small states in Europe, similar to India, but in contrast to what had happened in China. The