Missolonghi is built on the shores of a lagoon, so it was well protected from attacks on that side. But it remained vulnerable to raids from the mainland. During the 1770 Orlov revolt, the townspeople decided to construct a wall and a ditch around Missolonghi to protect themselves. When the Greek War of Independence broke out, the town became the seat of the provincial government and a military hub. The handful of Turks who lived there were expelled and the old wall was hastily repaired. In the fall of 1822 the town was besieged for two months but the Ottomans failed to breach the walls. It was clear though that the defences had to be upgraded, because the Turks would eventually return.