Write in detail about the expansion and development of the Janapadas.

The expansion and development of the Janapadas seem to have occurred in three different ways: 

• Expansion and development of a society formed into a Jana by uniting of a number of generations of a singular kula (family). For example, the Janapadas namely, Matsya, Chedi, Gandhara, Kashi, Kosala, etc. 
• Janapadas rising out of the union of more than one kula. For example, the Panchala janapada. Who were the five Janas united under the name of Panchalas, is not exactly known? According to the renowned historian, Hemchandra Raychaudhuri the following were the Janas who merged together as Panchalas: Krivi, Turvasha, Keshi, Shrinajaya, and Somaka. 
• The more powerful Janapadas conquered the less powerful ones.