Ksani fortress was built in 1511–14. In 1512 Bagrat, younger brother of King David X of Kartli (1505–25), asked for Mukhrani as his appanage and the command of the Shida Kartli banner; in return he undertook to fight Av-Giorgi, king of Kakheti. David agreed. Bagrat Mukhranbatoni built Ksani fortress as soon as he received his appanage lands. When Av-Giorgi learned of the fortress's construction, he came with an army and laid siege to it. The siege lasted three months, without result. Av-Giorgi mockingly sent Bagrat wine with the message: "You are a king's son, and how long it has been since you tasted wine." But Bagrat kept a live salmon in a well; he sent him the salmon with the reply: "You have stood on the Ksani for three months and have not tasted salmon — here, taste this live one." Av-Giorgi realized the fortress was well supplied with food and drinking water, lifted the siege and turned back