The Sea Peoples, from Cuneiform Tablets to Carbon Dating

The 13th century BC witnessed the zenith of the Aegean and Eastern Mediterranean civilizations which declined at the end of the Bronze Age, ∼3200 years ago. Weakening of this ancient flourishing Mediterranean world shifted the political and economic centres of gravity away from the Levant towards Classical Greece and Rome, and led, in the long term, to the emergence of the modern western civilizations. Textual evidence from cuneiform tablets and Egyptian reliefs from the New Kingdom relate that seafaring tribes, the Sea Peoples, were the final catalyst that put the fall of cities and states in motion. However, the lack of a stratified radiocarbon-based archaeology for the Sea People event has led to a floating historical chronology derived from a variety of sources spanning dispersed areas. Here, we report a stratified radiocarbon-based archaeology with anchor points in ancient epigraphic-literary sources, Hittite-Levantine-Egyptian kings and astronomical observations to precisely date the Sea People event. By confronting historical and science-based archaeology, we establish an absolute age range of 1192–1190 BC for terminal destructions and cultural collapse in the northern Levant. This radiocarbon-based archaeology has far-reaching implications for the wider Mediterranean, where an elaborate network of international relations and commercial activities are intertwined with the history of civilizations.


Introduction
The late 13 th century BC was a time of uncertainty and conflict for peoples and polities of the Aegean and Eastern Mediterranean [1,2,3]. Written evidences relate a weakening of central administrations [2], an erosion of political powers [4,5], and a widespread food shortage [6][7][8] underpinned by devastating drought [9,10]. This sequence of high-magnitude events led to the Sea People event and to the collapse of the ancient Mediterranean world around 1200 BC [1,3,5]. Cuneiform tablets foreshadowing the fall of the thriving coastal city Ugarit [2], and reliefs from Ramses III's mortuary temple at Medinet Habou depicting a chaotic scene of boats and warriors entwined in battle in the Nile delta [11], attest that vast movements of seafaring and inland tribes, the Sea Peoples [12] (or Land and Sea Peoples), lie at the heart of changes for this period.
The Sea Peoples were seaborne foes [13,14,15] from different origins [6,12]. They launched a combined land-sea invasion ( Fig. 1) that destabilized the already weakened power base of empires and kingdoms of the old world, and attempted to enter or control the Egyptian territory [11]. The Sea Peoples symbolize the last step of a long and complex spiral of decline in the ancient Mediterranean world [2,3,4,5]. Cuneiform tablets from Ugarit provide an impressive glimpse of the frantic preparations which the city and her neighbours pursued, in vain, to ward against the invasions [2]. The destructive operations of the Sea Peoples are later narrated by Ramses III who claims on his mortuary temple: ''No land could stand before their arms: from Hatti, Qode, Carchemish, Arzawa, and Alashiya on, being cut off (destroyed) at one time'' [16]. Within the conventional view, the Sea Peoples are linked in history to the collapse of the Late Bronze Age cultures [4], and 1200 BC stands as a symbolic date in human civilization.
Whereas the Sea People event constitutes a major turning point in ancient world history, attested by both written and archaeological (e.g. Ugarit, Enkomi, Kition, Byblos) evidence, our knowledge of when these waves of destructions occurred rests on translation of cuneiform tablets preceding the invasions (terminus ante quem) and on Ramses III's reign (terminus post quem). Here, we report the first absolute chronology of the invasion from a rare, well-preserved Sea People destruction layer (Fig. 2) from a Levantine harbour town of the Ugarit kingdom. The destruction layer contains remains of conflicts (bronze arrowheads scattered around the town, fallen walls, burnt houses), ash from the conflagration of houses, and chronologically well-constrained ceramic assemblages fragmented by the collapse of the town. This stratified radiocarbon-based archaeology, with anchor points in ancient epigraphic-literary sources, Hittite-Levantine-Egyptian kings and astronomical observations, was used to precisely date the Sea People invasion in northern Levant, a decisive episode in a long-term collapse of the ancient Eastern Mediterranean world. By confronting historical and science-based archaeology, the data offer the first firm chronology for this key period in human society.

The harbour town Gibala, Ugarit Kingdom
Sample collection for radiocarbon ( 14 C) dating of the Sea People event was performed at the harbour town Gibala [17,18,19], a thriving Levantine trade center located at the southernmost edge of the powerful Ugarit kingdom [20,21]. Gibala (present Tell Tweini, 35u22917.930N, 35u56912.600E; elevation: 19 to 27 meters above sea level ) was integrated into a large network of long-distance trading and cultural exchanges between the Aegean, Cyprus, the Levant, Egypt and Western Asia. Direct access from the Mediterranean to the Syrian heartland, Anatolia, and Mesopotamia afforded the ports of the Ugarit kingdom their wealth. This strategic position sets the chronology obtained for the destruction of Gibala by the Sea Peoples in a Mediterranean-wide perspective for the end of the Late Bronze Age (Fig. 1), extending over trade routes that crossed both land and sea. The place name Gibala appears on two 14 th century BC cuneiform tablets from Ugarit [17]. The written Bronze Age sources or epigraphic finds for Gibala cease as soon as Ugarit was destroyed by the Sea Peoples. Gibala-Tell Tweini is a large multi-period site of ,12 hectares (Fig. 2), which was occupied from Early Bronze Age IV (2400 BC) to Iron Age III (500 BC). During the past 11 years, large-scale  excavations have elucidated a thriving Bronze Age city that remained occupied during the Iron Age, with only short periods of abandonment despite a massive fire at the end of the Early Iron Age [short-lived sample: 2845635 14 C years before the present ( 14 C yr BP from AD 1950)] (Fig. S1) (Supporting Information S1). Gibala is a rare coastal settlement, alongside Tell Kazel, Ras Ibn Hani and Ras el-Bassit, with reoccupations after the Sea People event. A stable water supply, provided by the northern Rumailiah River and the southern Ain Fawar spring-complex, may explain resettlements on the Gibala's alluvial plain since the Early Iron Age [10].

Results and Discussion
About 300 years after a first conflagration (short-lived sample: 3190640 14 C yr BP) ( Table 1) (Supporting Information S1), the site was abandoned following a severe destruction at the end of the Late Bronze Age (Fig. 2). The widespread ash layer, termed Level 7A, contained rich finds (Fig. 3) including bronze arrowheads resulting from fights in the harbour town before its destruction, and a large variety of Mycenaean (Late Helladic IIIB), local Late Helladic IIIC Early, and Late Cypriot IIC ceramics (e.g. White slip II) highly significant for the Sea People event in the ancient Mediterranean world [17,18]. This ash layer is nearly synchronous with the Sea People destruction of Ugarit, and other northern Levantine coastal sites such as Ras Ibn Hani, Ras el-Bassit, Tell Kazel, and Tell Sukas [17]. Short-lived samples and young branches found in the destruction debris from eight key loci (Fig.  S2) were dated by accelerator mass spectrometry (AMS). The samples pooled in the matrix (Table 1) are statistically the same at the 95% confidence level using a Chi-square (x 2 ) test (sample key 7, where T = 6.09,14.1). The weighted average date (2962614 14 C yr BP) gives a 1 sigma (s) calibrated age range of 1215-1190 BC with 34.3% relative probability and another age range of 1180-1160 BC with 26% relative probability, using Calib-Rev. 6.0.1 [22] and Oxcal 4.1 [23] with IntCal09. Calibrated age ranges in details at 60.3% of the 100% dating probability (Fig. 4). Hence, there are two chronological possibilities for the calibrated date of the destruction Level 7A, between the end of the 13 th century and the beginning of the 12 th century BC or the first half of the 12 th century BC. By contrasting historical-archaeological and radiocarbon-based data sets, the best candidate for the destruction date of the harbour town is the Sea People invasion. Their presence immediately after the destruction of Gibala is indicated by the material culture of the new settlements on the Tell namely the appearance of Aegean-type architecture, locally-made Mycenaean IIIC Early pottery, hand-made burnished pottery, and Aegean-type loam-weights. These materials, also known from Philistine settlements [24], are cultural markers of foreign settlers, most probably the Sea Peoples.
The internal consistency of the typical imported ceramic assemblage found in the destruction layer (Fig. 3) and the 14 C dating results (Fig. 4) indicate that Level 7A is a secured layer to date the Sea People event in northern Levant. The Late Helladic IIIB-IIIC (Early) and Late Cypriot IIC-IIIA transitions respectively dated in mainland Greece to 1210-1175 BC [25] and in Cyprus to 1220-1190 BC [26][27], are markers for the end of the palatial civilization in both the Aegean and Cyprus. All the Mycenaean imports ended in the region of the Ugarit kingdom with its destruction by the Sea Peoples who interrupted trade routes. Neutron activation analyses suggest that the Late Helladic IIIB vessels found at Gibala until the 13 th century BC originate from the northern Peloponnese area [19]. The Late Cypriot IIC ceramics were imported from Cyprus. The 14 C dating results of Gibala are closely matched with historical dates suggested by Egyptologists for the reign of the Pharaoh Merneptah (1213-1203 BC), and Pharaoh Siptah-Queen Tawsret (1194-1186 BC) [28] (Fig. 4) [2]. These letters demonstrate that Ugarit was still a kingdom at the very end of the 13 th century BC but also relate that its territory was threatened by seaborne and land invasions (Fig. 1). The cuneiform tablet RS 86.2230 [29], sent by the Egyptian Bay (1194-1190 BC), the Great Chancellor of the Pharaoh Siptah-Queen Tawsret, to the last king of Ugarit provides the final evidence of a living kingdom at the dawn of the 12 th century BC. A document from Egypt relating the execution of Bay as a traitor in Siptah's regnal year 5, states that the cuneiform tablet RS 86.2230 must have been written before an historical date of 1190 BC [30].
The radiocarbon results, in relation to archaeological and historical data, lead us to propose a date of 1194-1190 BC for the Sea People event in the northern Levant. This radiocarbon-based archaeological date can be refined with the astronomical observation related on the cuneiform tablet KTU 1.78 (RS 12.061) found among the ruins of Ugarit. The sun eclipse depicted on the cuneiform tablet KTU 1.78 was dated to the 21 January 1192 BC [31], suggesting that the destruction of the city and the fall of the kingdom occurred after this observation. The date of 1192-1190 BC for the Sea People invasions in the northern Levant, and the end of the ancient Eastern Mediterranean world fits the radiocarbon, historical, archaeological and astronomical data.
Our research suggests that the traditional Egyptian date for the decline of the ancient Mediterranean world, based on sources from Ramses III's reign, only corresponds to the final part of a more complex and longer-term event that intensified after 1215 BC with the first written evidence of food shortage [6,7,8]. According to the Great Harris Papyrus and to the scenes of naval and land battles depicted at Medinet Habu (Thebes, Upper Egypt), Ramses III defeated the Sea Peoples during the 8 th year of his reign [11]. The first regnal year of Ramses III is variously dated in the literature [28,32,33], giving historical dates of 1176 BC, 1179 BC, and a By a combined use of radiocarbon, archaeological and historical data, the first firm date of 1192-1190 BC is proposed for the terminal destruction and disintegration of Late Bronze Age societies in the Northern Levant. The collapse caused by the Sea Peoples marks a historical watershed and from these crisis years arose a new world. Later, the Greeks narrated and heroised this period with the myths and stories on the fall of Troy (Homer's Iliad and Odyssey). Some of the Sea Peoples, the Philistines [12], received a significant recognition in Biblical texts [34], and the name Palestine derives from these settlers.

Materials and Methods
Quality control on sample collection for 14 C measurements was undertaken during excavations. Only samples originating in reliable contexts with clear association to meaningful ceramic assemblages and occupation levels were used. Samples were selected from primary contexts in May 2010, with an emphasis placed on short-lived samples (seeds or olive stones) (Fig. S2) and young branches (Fig. S3). All botanical macro-remains were sampled from the Middle-Late Bronze Age to the Iron Age II layers and subsequently determined using optical and scanning electron microscopes (Fig. S2). A total of 24 secured samples were dated by Beta Analytic (Miami, Florida) and Poznan Radiocarbon Laboratory (Poznan) using standard accelerator mass spectrometry 14 C. An acid/alkali/acid pretreatment was performed and the radiocarbon ages were measured. The 13 C/ 12 C ratio and the conventional radiocarbon age were provided for each sample with two-sigma calendar calibration results. The weighted average value for the fire event termed Level 7A results from multiple measurements of the same ash layer from different key loci. The samples pooled in the matrix were statistically tested at a 95% confidence level using a x 2 test. The weighted average value was calibrated using Calib. Rev. 6.0.1 [22] and Oxcal 4.1 [23].