The Ottomans responded by dispatching a naval force to the coast of Epirus but the rebels managed to retreat inland and took advantage of the mountainous terrain. Additionally, in the summer of 1569, an Ottoman fortress was erected in a strategic location in Mani to monitor rebellious activity. After a short decline, the rebellion reached a new momentum and the newly erected fortress was captured in the summer of 1570 with the support of a Venetian force. Following the outbreak of the Ottoman–Venetian War in 1570, Venetian units also assisted the revolutionaries in Himara in the capture of the castle of Sopot on the Ionian Sea coast after a two-month siege in June 1570. The uprising spread to various parts of Epirus under Emmanuel Mormoris, with the guidance of local Greek nobles and various Stratioti military leaders such as Petros Lantzas. The castle of Nivica was also taken in March 1571.