Its exact date of formation is not known but likely it predates 1400 CE as under the Devagiri Yadavs(1248- 1318) and under theTughlaq rulers(1318-1347), Karnala was the capital of the north Konkan districts of their respective empires. It later fell under the command of the Gujarat Sultanate but in 1540 was taken over by Nizam Shah of Ahmednagar. The Gujarat sultans then requested the help of the Dom Francisco de Menenzes the commanding officer of the Portuguese at Bassien(modern day Vasai) to win it back. He ordered 500 of his solidiers to Karnala fort and they were able to capture it. The fort was left in charge of the Gujarat Sultanate but with Portuguese garrisons.
The loss of Karnala enraged the Nizam Shah and he took back the fort and the surrounding countryside by sending 5,000 of his men. The Gujarat sultans fled to Vasai in panic and gave up any claims of the fort to the Portuguese. In the subsequent battle between the Nizam Shah and the Portuguese, the latter were victorious in repulsing further attacks of the Nizam Shahi army and the fort remained with the Portuguese. However the Portuguese Viceroy determined that the forts of Sangli and Karnala were of little value to them and decided to give them to the Nizam Shah for an annual payment of Rs. 17,500(or 5,000 gold pardoas) to further their friendship
Shivaji conquered it from the Portuguese in 1670 by building breastworks as he advanced After his death in 1680 it was taken over by Aurangzeb. After this the Mughals occupied it for some time after which it in 1740 with the rise of the Peshwas of Pune it went to them. It remained under the command of killedar(garrison commander) Anantrao until a colonel Prother won the fort and established the rule of the British East India Company there in 1818.
VALLEY VIEW FROM FORT
ENTRY GATE TO KARNALA FORT BOMBAY
KARNALA FORT WALLS