Short answers, pulled from the story.
The Maurya Empire was founded by Chandragupta Maurya around 320 BCE. He defeated the Nanda dynasty and established the empire with its power base in Magadha, with the capital at Pataliputra, the site of modern Patna.
According to the Greek ambassador Megasthenes, the Mauryan military comprised 600,000 infantry, 30,000 cavalry, 8,000 chariots, and 9,000 war elephants, alongside followers and attendants. Military command was organized into six boards of five members each, covering the navy, transport, infantry, cavalry, chariot divisions, and elephants.
Ashoka conquered Kalinga in 261 BCE. An estimated 100,000 soldiers and civilians were killed and hundreds of thousands more were adversely affected. After personally witnessing the devastation, Ashoka embraced Buddhism, renounced expansion, banned hunting and violent sports, abolished slave trade, and began a massive programme of public works and Buddhist missions.
In July 1947, Jawaharlal Nehru proposed to the Constituent Assembly of India that the 24-pointed Buddhist Wheel of Dharma from the Lion Capital of Ashoka at Sarnath become the central feature of India's national flag. The proposal was accepted in December 1947.
The Buddhist tradition holds that the dynasty's ancestors settled where peacocks were abundant and became known as the Moriyas, meaning "belonging to the place of peacocks." The Jain texts link the name to an ancestor who was an imperial superintendent of peacocks. The name Maurya does not appear in Ashoka's own edicts or in contemporary Greek accounts; its earliest written attestation is the Junagadh rock inscription of Rudradaman, dated to around 150 CE.
In 180 BCE, Brihadratha, the last Mauryan emperor, was killed by his general Pushyamitra Shunga during a military parade, with no heir in place. The Shunga Empire rose immediately afterward. The fall left the Khyber Pass unguarded, and around the same year the Greco-Bactrian king Demetrius conquered southern Afghanistan and parts of northwestern India, forming the Indo-Greek Kingdom.