The Licchavis turned to be great rivals of Magadhan monarchy. In the reign of Bimbisara of Magadha, they invaded the Magadhan kingdom. In the reign of Ajatasatru, a protracted war began between Magadha and the Lichchhavis. The latter were united with the Vajjis in a confederacy. In the struggle that followed the Lichchhavis and the Vajjis were destroyed.
The causes of the Magadha-Lichchavi war were many. Ajatasatru wanted to take revenge on the Lichchhavis, as their chief Chetaka had refused to extradite Ajatasatru’s step brothers. They had escaped to Vaisali (Licchavi capital) with the royal elephant and family jewels and were granted political asylum. The real cause of the Magadha-Licchavi war was the aggressive imperialism of Magadha against the neighboring republic. The war continued for sixteen years. The Lichchhavis built a mighty alliance with the Vajjis and the other thirty six Ganarajas and also with the kingdom of Kasi-Kosala against Magadha. But the ministers of Ajatasatru sowed seeds of discord among the members of the anti-Magadhan confederacy and destroyed their unity. Ultimately the Vajjian confederacy was destroyed by Ajatasatru. The Vajji territory was annexed to Magadha.