The massive “Spring Tower” built over Jerusalem’s Gihon Spring was originally dated by archaeologists to the Middle Bronze Age. A new study, however, indicates that the fortifications were constructed in the 9th century BC, the time when Jerusalem was ruled by Jehoshaphat and Joash. The new dating is based on radiocarbon dating of material found in sediment underneath boulders at the tower’s base.
The previous discovery and dating to the 18th century BC radically changed our understanding of the development of the city, suggesting that Jerusalem was home to an advanced civilization about eight centuries before David’s conquest. This new re-dating will force the re-writing of the city’s history, not only in Canaanite times but in the Judahite period as well.
One can speculate what might have prompted such construction and which king it occurred under. I haven’t read the full study (available here for $35), but from other research I wouldn’t put too much weight on the date, as radiocarbon dates in the 9th century usually have quite a bit of flexibility. But if the tower dates earlier than the time of Hezekiah, one can only wonder why he considered the relatively recent fortification insufficient and the need to construct a water tunnel essential.
A summary of the research is posted at the website of the Weizmann Institute of Science.
HT: Joseph Lauer