Origin of Letter War

http://warencyclopedias.blogspot.in/2011/10/origin-of-letter-war.html

Successive Dynasty

After Dwarka Got Submerged - The Dynasty of Yadavas were Continued in

1. Hastinapur by pariksheet maharaj the grandson of Arjuna and Subadra(Female Side)
2. Indraprastha by Vajra the  great grandson of Krishna and Rukmini the grandson of Pradyumna, and the son of Aniruddha.(Male Side)

Source
http://finalemperor.blogspot.com/2013/11/vajra.html