Magadha was an ancient Indian kingdom in southern Bihar, and was counted as one of the sixteen Mahajanapadas, 'Great Kingdoms' of ancient India. Magadha played an important role in the development of Jainism and Buddhism, and two of India's greatest empires, the Maurya Empire and Gupta Empire, originated in Magadha.

Magadha the modern Bihar. It was very powerful Mahajanpada as it Conquered other mahajanpada regions. The rulers married with the daughter of other rulers to expand their powers. The other mahajanpadas later became the part of Magadha. There were few kingdoms where people choose the rulers by their own. These type of kingdoms were known as Ganasanghas. Now we will talk about the rulers of Magadha.
The first ruler of Magadha was Bimbisara. He ruled from 542-492 BCE. He was wise and visionary ruler. He conquered many states and Expand his power and empire he never did injustice with his people. he established his capital rajghira near Patna . he was succeeded by his ajatshatru.
He killed his father to gain Supreme powers he was the second ruler of Magadha. He ruled from 492-460 BCE. After that pataliputra was the capital of Magadha in village patli on the bank of river Ganga. He conquered Vaishali , Kashi and Kosala and expand his Empire. He send a detective to Lichchavi to get every news from there. he was the devotee of Mahatma Budh and Mahavir. According to purans the third ruler of Magadha was Darshak. after the death of ajatshatru he became the king of Magadha. Nandas and Shishungas was two important dynasties of Magadha. Magda attend very distinguished position under the nandas. the first ruler of Nanda dynasty was mahapadma Nanda He was succeeded by his son dhanananda . However the information about these two rulers is very less. After these two rulers ghanananda was the last and third ruler of nanda dynasties. Ghananand ruled from 345 BCE to 322 BCE. He was very unpopular ruler. During the rule of ghanananda , the son of King Philip of Macedonia, Alexander attacked India and defeated king poras. He wanted to conquer Magadha but was not successful.
Chanakya a Brahman guru was insulated by ghanananda. He pleged to destroy the Empire of Nanda. He met Chandragupt maurya and collected a team of soldiers and conquered Sindh and Punjab. They defeated ghanananda and established Mauryan dynasty in 324 BCE.
After the decline of nanda ruler a new dynasty rise mauryan dynasty. The first ruler of Mauryan dynasty was Chandragupta Maurya. He established a great empire. He ruled from north to south and east to west including Balochistan and Afghanistan in Pakistan. The prime minister and guru of Chandragupta was chanakya. He wrote a book on political administration arthshastra. The information about Chandragupta is limited. He was succeeded by his son Bindusar. He was second ruler of Mauryan dynasty. He ruled from 297 BCE to 272 BCE. He was very wise and brave ruler. He protect his empire from enemies. He had good relations with Greek . After his death Ashoka was the third ruler of Mauryan dynasty. He ruled from 272 BCE to 232 BCE. He succeeded his father in 272 BCE but crowned in 269 BCE. He is the greatest ruler in world history . after the Kalinga war His life was totally changed he pledged never to resort war. Because there was a huge loss of life and property. That's why the fierce battle of Kalinga war is known as the turning point of Ashoka. In 232 BCE , after the death of Ashoka the decline of Mauryan empire started. The main reason for decline of Mauryan dynasty was Ashoka's pledge never to resort war. The last ruler of Mauryan dynasty was brihadratha Maurya. His commander in chief pushya Mitra sunga killed him and captured the throne. He was the founder of sungas dynasty. And was succeeded by agni Mitra sunga. Devbhuti was the last ruler of sungas dynasty was killed by the founder of kanva dynasty Vasudeva in 72 BCE .