Throughout its long history, Jerusalem has been destroyed at least twice, besieged 23 times, captured and recaptured 44 times, and attacked 52 times. The part of Jerusalem called the City of David shows first signs of settlement in the 4th millennium BCE, in the shape of encampments of nomadic shepherds. In the Canaanite period (14th century BCE), Jerusalem was named as "Urusalim" on ancient Egyptian tablets, probably meaning "City of Shalem" after a Canaanite deity. During the Israelite period, significant construction activity in Jerusalem began in the 9th century BCE (Iron Age II), and in the 8th century the city developed into the religious and administrative center of the Kingdom of Judah. In 1538, the city walls were rebuilt for a last time around Jerusalem under Suleiman the Magnificent. Today those walls define the Old City, which has been traditionally divided into four-quarters—known since the early 19th century as the Armenian, Christian, Jewish, and Muslim Quarters. The Old City became a World Heritage Site in 1981, and is on the List of World Heritage in Danger. Since 1860 Jerusalem has grown far beyond the Old City's boundaries. In 2015, Jerusalem had a population of some 850,000 residents, comprising approximately 200,000 secular Jewish Israelis, 350,000 Haredi Jews and 300,000 Palestinians. In 2016, the population was 882,700, of which Jews comprised 536,600 (60.8%), Muslims 319,800 (36.2%), Christians 15,800 (1.8%), and 10,300 unclassified (1.2%).