The Asai's origins are obscure but they may have been descended from the Ôgimachi, a kuge family. The Asai were formerly retainers of the Kyôgoku and rebelled against that house in 1516. They struggled to expand their domain in Ômi at the expense of the Rokkaku and came to eclipse the Kyôgoku. In the process close ties were forged with the Asakura of Echizen. The Asai broke an alliance with Oda Nobunaga in 1570 and were eliminated in 1573. 'Asai' is often pronounced 'Azai'.