Tel Burna’s prominent summit, encompassed by a 70 × 70 m casemate fortification, has attracted attention since at least the nineteenth century CE. An analysis of the archaeological data collected during ongoing excavations at the tell indicates that these fortifications were built in the late tenth or early ninth century BCE. The fortification of this Judahite stronghold, located on the border with Philistia, remained in use for the next 200 years. Recently, evidence has come to light of a massive undertaking to reinforce and strengthen the western side of the casemate wall in the late eighth century BCE. The authors identify these activities as part of the preparations made to defend the city from Sennacherib’s campaign in the region. The site was subsequently re-inhabited, but the fortifications seem to have gone out of use during the last stage of the occupation at the end of the Iron Age.