Initially, a C14 date of 1410 +/- 40 B.C. (done by the British Museum) was published for charcoal from the destruction level of Jericho (Jericho V , p. 763). This was later found to be in error and corrected from 3080 +/- 40 BP to 3300 +/- 110 BP (Radiocarbon 32 : 74; BP = before present), which calibrates to 1590 or 1527 +/- 110 B.C., depending on how one reads the calibration curve (Radiocarbon 35 : 30). Additional tests were done on six grain samples from the destruction level resulting in dates between 1640 and 1520 B.C. and 12 charcoal samples from the destruction level resulting in dates between 1690 and 1610 B.C. (Radiocarbon 37 : 217). More recently, the Italians obtained two samples from a structure at the base of the tell that yielded dates of 1347 +/-85 and 1597 +/-91 B.C. (Quaderni di Gerico 2 : 206–207, 330, 332). The locus the samples were taken from appears to contain debris from the final Bronze Age destruction of the city.
My dating of the destruction of Jericho to ca. 1400 B.C. is based on pottery, which, in turn, is based on Egyptian chronology. Jericho is just one example of the discrepancy between historical and C14 dates for the second millennium B.C. C14 dates are consistently 100–150 years earlier than historical dates. There is a heated debate going on among scholars concerning this, especially with regard to the date of the eruption of Thera (Santorini). The literature on the subject is enormous, so I will not attempt to give you references. A recent overview can be found in Manfred Bietak and Felix Höflmayer, Introduction: High and Low Chronology, pp. 13–23 in The Synchronisation of Civilisations in the Eastern Mediterranean in the Second Millennium B.C. III, eds. Manfred Bietak and Ernst Czerny, Vienna: Österreichischen Akademie der Wissenschaften, 2007. Because of the inconsistencies and uncertainties of C14 dating, most archaeologists prefer historical dates over C14 dates.
Editorial note: The evidence for the destruction of Jericho at the time the Bible describes it and the way the Bible describes it is overwhelming. Dr. Wood has done extensive work on this subject. Articles pertaining to this all important Biblical subject can be found here on the ABR website:
The Walls of Jericho
Did the Israelites Conquer Jericho? A New Look at the Archaeological Evidence
Extra-Biblical Evidence for the Conquest
See Dr. Wood discuss the evidence in this cutting edge video, Jericho Unearthed. Jericho Unearthed can be purchased in the ABR bookstore.
See Dr. Wood present his research on Jericho in this video from 2009.