The basis of the three-age system, emphasizing archaeological periods, is the 1819 work of Danish archaeologist Christian J. Thomsen (1788–1865). He related the classification of artifacts to technology, that is, according the materials in which made (stone, bronze, and iron), thereby defining the Stone Age, the Bronze Age, and the Iron Age. See table below for the Levantine Archaeological Periods based upon the three-age system.

Thomsen developed the three-age system as a means for the display of artifacts for the Museum of Northern Antiquities (now the National Museum of Denmark). Thomsen held that the three-age system had chronological significance where stone preceded bronze, and bronze preceded iron. The “Law of Association” arose from this presumption. The Law of Association is that objects placed in a grave as part of a burial generally consist of things in use at the time of interment.

Jens Jacob Asmussen Worsaae (1831–1835), a later associate of Thomsen succeeded him at the museum. Worsaae, now generally acknowledged as the first true professional archaeologist, field-tested the three-age system and verified the Law of Association. He found that in undisturbed graves that grave goods found together generally consisted of objects in use at the time of interment. Archaeologists quickly recognized the general application of the three-age system to archaeological work.

Sir John Lubbock (1834–1913) later further subdivided the Stone Age into Paleolithic and Neolithic periods. Late in the nineteenth century, the Mesolithic period became recognized. Further refinements have continued to the present day (see table). In geological time, the Paleolithic Period belongs to the Pleistocene Epoch. The Mesolithic Period to the present day is of the Holocene Epoch.

The Three-Age System in the Levant

Period	Dates	Description
Roman	63 BCE–324 CE	Roman occupation
Hellenistic	333–63 BCE	Decided Hellenistic influence
Persian	586–333 BCE	Persian control
Iron II–A, B, C	1000–586 BCE	Israelite II
Iron I–A, B, C	1200–1000 BCE	Israelite I
Late Bronze–I, IIA, IIB	1550–1200 BCE	Late Canaanite
Middle Bronze–I, IIA, IIB, IIC	1950–1550 BCE	Middle Canaanite
Early Bronze–IVA, IVB/Middle Bronze–I	2300–1950 BCE	Transition from EB to MB
Early Bronze–I, II, III	3300–2300 BCE	Early Canaanite
Chalcolithic	4300–3300 BCE	Ghassulian Culture
Neolithic	8500–4300 BCE	“New Stone Age” Yarmukian Culture (emergence of herding and agriculture)
Mesolithic	10,500–8500 BCE	“Middle Stone Age” Natufian Culture (hunters & gathers)
Paleolithic	2 million years	“Old Stone Age” Pleistocene

The Wheeler–Kenyon Method (earth layers analysis) of excavation emphasizes the vertical dimension through analysis of earth layers, or strata, and their contents. Vertical control comes from the use of the balks separating grid squares. Horizontal control comes from keeping the working surface of the  square level for any given locus and proper three-dimensional recording.

The Wheeler–Kenyon method bares the name of the two archaeologists credited for developing it—Mortimer Wheeler and Kathleen Kenyon. The Albright–Wright Method (architectural approach) of excavation stresses the wide-scale exposure of complete architectural units.

The prevailing Levantine approach, with a focus on interpretation, not explanation, emphasizes a combination of the earth layers analysis and the architectural approach wherein excavations proceed through earth layers analysis including the exposure of complete architectural units (through grid squares and balks.

This approach supports both processual scientific) and postprocessual (postmodern) archaeological research although the latter prevails in contemporary Levantine sites. A criticism of the approach consists of the problem that exposure of complete units does not leave the opportunity for re-excavation with improved techniques by subsequent generations.