The Son River forms a natural boundary between Bihar and Jharkhand states for a considerable stretch. It is a tributary of the Ganges and flows through both states.

The Mithila region (North Bihar) experiences severe seasonal flooding primarily due to heavy monsoonal rains and the overflow of rivers like Kosi and Mahananda that originate in the Nepal Himalayas, which receive substantial snowmelt and precipitation.

Pataliputra was the capital of the Mauryan Empire and continued to be significant during the Shunga period. It was one of the largest cities in the ancient world with well-organized administration, walls, and public structures.

Vikramashila University was founded by King Dharmapala of the Pala Dynasty in the 8th century CE in Bihar.

Jayaprakash Narayan (JP) was a prominent Bihari freedom fighter who played a vital role in the Quit India Movement of 1942.

The Barabar Caves, one of India's oldest rock-cut caves, are situated in Jehanabad district and date back to the Mauryan period.

Sonepur Mela is held at the confluence of Ganges and Son rivers in Saran district, attracting livestock traders from across India.

Bihar was separated from Odisha (Orissa) in 1936 through the Government of India Act, forming a separate province.

Kunwar Singh of Jagdispur in Bihar was a prominent leader during the Sepoy Mutiny of 1857 against British colonial rule.

Rajgir was the ancient capital of Magadha kingdom and served as a major center of power and learning during the Mauryan and subsequent periods.