The Maurya Empire was founded by Chandragupta Maurya with help from Chanakya at Takshashila in the year 322 BC. Chandragupta defeated King Dhana Nanda of the Nanda Dynasty to establish the Mauryan Empire. At the peak of its power, the empire stretched from Afghanistan to Bay of Bengal to southern India. It was the largest ever in the Indian subcontinent and one of the world's largest empires at its time. The dynasty ruled from 322 BC to 185 BC. A total of nine rulers rule the empire among which Ashoka was the greatest. Pataliputra was the capital of the Empire. It was about nine mile in length and a mile and a half in breadth. According to Megasthenes, it was "surrounded by a wooden wall pierced by 64 gates and 570 gates.
Chandragupta Maurya ruled the empire for 27 years. Chanakya served as the chief advisor to Emperor Chandragupta. "The Arthashastra" which is India's oldest and most influential policy and military strategy book was written by Chanakya.
Bindusara was the son of the first Mauryan emperor Chandragupta Maurya and his queen Durdhara. He succeded Chandragupta Maurya after his death at the age of 22 and ruled for 25 years. Bindusara extended this empire to the southern part of India, as far as what is now known as Karnataka. Bindusara died in 272 BCE and was succeeded by his son Ashoka.
Ashoka, who served as the viceroy of Ujjaini during his father's reign, become the third Emperor of Mauryan dynasty. He ruled form 268 BCE to 232 BCE. He started the preparation for the conquest of Kalinga soon after he became the King of Magadha. The conflict took place around 261 BCE and it is considered one of the most brutal and bloodiest wars in world history. Ashoka, who led the campaign in person, was stuck by the horrors of the war and the amount of misery and bloodshed it involved. Although Ashok defeated Kalinga, but the feeling of remorse and misery led Ashoka to embrace the Buddhist religion. Ashoka implemented principles of ahimsa (non-violence) by banning hunting and violent sports activity and ending indentured and forced labor. Ashoka embraced the teachings of Buddhism, and renounced war and violence. The Emperor organised a network of missions to preach the gospels in countries far-off and near. Ashoka issue set of edicts known as Edicts of Ashoka that formed a policy of the Mauryan emperor Ashoka. The Edicts of Ashoka are a collection of 33 inscriptions that found in different places in his kingdom. The four lions of Sarnath, has become the State Emblem of India. Ashoka ruled for an estimated 36 years.
Ashoka died about 232 BC and seven kings followed him in regular succession, during a period of fifty years. Brihadratha was the last ruler of the Mauryan dynasty. Brihadratha was assassinated in 185 BCE during a military parade by the Brahmin general Pushyamitra Shunga, who then took over the throne and established the Shunga dynasty.