There were many states of the Aryans in North India, around the 6th century B. C. These states were called the 'Mahajanapadas'. The Mahajanapadas of Anga, Kashi, Kosala, Chedi, Vatsa, Matsya, Shursen, Ashmak, Avanti, Gandhar and Magadha were ruled by kings or monarchs. The kings in these states had the supreme authority. The Mahajanapadas of Vrijji, Malla, Kuru, Panchal and Kamboj were republican states and so were other smaller states like Lichhavi, Shakya, Koliya, Bhagga, Moriya. These republican states had a 'Gana-parishad' or an Assembly of senior and responsible citizens. This, Gana-parishad had the supreme authority in the state. All the administrative decisions were taken by this Parishad. Of all these states, Kosala, Vatsa, Avanti and Magadha were the most important ones. Kosala: Shravasti Kushavati, Saket, and Ayodhya were the famous cities of Kosala. Ayodhya was the State capital. The Kosala king Prasenajit was - a contemporary of Gautama Buddha. Kosala and Magadha went to war during his reign. The independent state of Kosala did not last -long after Prasenajit. Vatsa: Kaushambi of the present day Bihar, was the capital of Vatsa. Vatsa was famous for its fine cotton cloth. The Vatsa king Udayana was very brave. He was the follower of Gautama Buddha. The independent status of- Vatsa was soon lost after king Udayana. Avanti: The kingdom of Avanti comprised the area around the present day Ujjain in Madhya Pradesh. Pradyota, the king of Avanti, was a very ambitloys ruler. He was constantly engaged in conflicts with Kosala, Vatsa and Magadha. In this constant warfare, the Magadha state ultimately proved superior. Magadha: Expansion of the Magadha kingdom started during the reign of King Bimbisara. He annexed the kingdoms of Kashi, Madra and Anga to Magadha. There is a reference in the Buddhist works to 80,000 village in Bimbisara's kingdom. The capital of his kingdom was Rajagriha, the present day Rajgir in Bihar. The city of Rajagriha and King Bimbisara's palace were built by an architect named Mahagovinda.