Upon reading the letter, Krishna immediately set out for Vidarbha with his elder brother Balarama and an army. He did not wait for an invitation.
However, her brother Rukmi, a proud and powerful prince, despised Krishna. Against Rukmini’s wishes, Rukmi arranged her marriage to Shishupala, the evil king of Chedi (and Krishna’s cousin, though they were enemies). Shishupala was an ally of Rukmi and the Kauravas.
Rukmi, enraged, chased Krishna with a massive army. A fierce battle ensued. Rukmi challenged Krishna and was defeated. Krishna was about to kill Rukmi, but Rukmini begged for her brother’s life, falling at Krishna’s feet. Krishna spared Rukmi but as punishment, shaved his head (a great dishonor for a prince) and let him go.