Maharaja Pandu had five sons and Dhrtarastra had one hundred sons. So it is family, the same family, and it was understanding between them that when others beyond the family would come to attack them, they would join, 105 brothers, and fight. But when there was fight amongst themselves - one side, hundred brothers; one side, five brothers. Because a ksatriya family, it is to be understood they must go on fighting. Even in their marriage there would be fighting. Without fighting, no marriage takes place in ksatriya family. Krsna had 16,108 wives, and almost in each time He had to fight, to gain the wife. It was a sporting. For ksatriya to fight, it was a sporting.
Lecture on Bhagavad-gita 2.6, London, August 6, 1973