Estimate Ashoka's place in history?Why is he called Ashoka the Great?

List out principles of Dhamma.

'Ashoka led his life by example.'Justify this statement.

Who was the most famous ruler of the Mauryan dynasty?How did he try to reach his message to the people?

Due to paucity of time all aspects of your query could not be resolved:

1) Ashoka was the most famous Mauryan ruler. He fought a war to capture Kalinga, where he was horrified to see the violence and bloodshed. Thereafter, he tried to spread the message of peace by adopting dhamma and the teachings of the Buddha. He was the first ruler to have got his messages inscribed on rocks and pillars. Ashoka treated his subjects like his children and appointed officials to teach his dhamma. He was a great administrator and built roads and rest houses and dug wells for the comfort of people. He sent messengers to spread the message of dhamma to countries like Syria, Egypt, Greece and Sri Lanka. His description and of the Mauryan Empire and its capital Pataliputra was provided by Megasthenes, an ambassador of the Greek ruler Seleucus Nicator.