Among the many mahajanapads existing during the later Vedic period, Magadha was the most powerful. Among various factors which took Magadha to the top one was that it was ruled by shrewd rulers like Bimbisara and his son Ajatasattu. Along with taking care of their subjects, they continued to capture other janapads to expand Magadha.
Mahapadma Nanda, another important ruler of Magadha extended it further to the north-western part of the subcontinent. The initial capital of Magadha was Rajghriha and later it was changed to Pataliputra. Magadha territory had a beneficial location as river Ganga and Son flowed through it, making it fertile throughout and providing water for both agriculture and other chores.
The rivers not only acted as natural barriers but were also used to transport goods and supplies to the army in the battlefields far away. Magadha also was surrounded with rich deposits of iron ore, used for making tools and weapons; dense forests, used to get high-quality wood for building houses, carts and chariots. Also, the elephants that were captured from these forests were trained for the army.
Another mahajanapad Vajii, with the capital as Vaishali, became the first kingdom to practice the democratic form of government called sangha or gana. In this form of government, unlike just one Raja, there were many rajas, who met in assemblies to discuss and debate on the important issues. A decision was taken only after consulting all the Rajas. The system of sanghas or ganas lasted until 1,500 years ago.