| The first excavation of the site was
undertaken between 1903 and 1905 on behalf of the German Society for the
Study of Palestine by Gotlieb Schumacher, an engineer who lived in the German
community of Haifa.  Schumacher cut a 65-foot-wide
trench across the mound from north to south and a number of smaller trenches
in other parts of the site, identifying six building levels. His most famous
find is a jasper seal portraying a roaring lion and inscribed "(belonging)
to Shema, servant of Jeroboam." Shema was apparently a high official of
the king of the northern kingdom, either Jeroboam I (end of tenth century
B.C.E.) or Jeroboam II (eighth century B.C.E.). This striking emblem of
a powerful lion was sent by Schumacher to the Turkish Sultan in Constantinople,
who kept it there in his royal collection. It is not clear what happened
to it later, but today its whereabouts are unknown.|
| In 1925, excavation
at Megiddo resumed under the auspices of the Oriental Institute of the University
of Chicago. Initiated by its famous director, Egyptologist James H. Breasted,
it was led by Clarence Fisher, who was succeeded by P.L.O. Guy, who was
succeeded by Gordon Loud. Large-scale work nevertheless continued until
the outbreak of World War II in 1939.
With a generous grant from John D. Rockefeller, the Oriental Institute team operated on a grand scale, including the use of a balloon for aerial photography and the construction of their own beautiful expedition house complete with tennis courts. The expedition house now serves as offices for the Israel National Parks Authority.
THE SHEMA SEAL. A roaring, muscular
lion adorns a tenth- or eighth-century B.C.E. seal that reads "(belonging)
to Shema, servant of Jeroboam." Shema was apparently a high-ranking
official in the court of either Jeroboam I, who ruled the northern kingdom
of Israel in the late-tenth century B.C.E., or Jeroboam II, king of
the northern kingdom from 793-753 B.C.E. The seal pictured here is a
replica. The original, made of jasper, was discovered at the beginning
of this century by Gotleib Schumacher, Megiddo’s first excavator, who
gave it as a gift to the Turkish Sultan in Constantinople; it subsequently
disappeared and its whereabouts today remain a mystery.
The original goal of the Oriental Institute excavators was to "peel off," one by one, each layer of habitation at the site, finally reaching bedrock. This was a critically defective methodology, on two counts. First, it was such a gargantuan task that it was impossible to complete, even with Rockefeller money behind it.
When this became evident to the excavators, they abandoned the "peel-off strategy" and instead concentrated their efforts in selected areas.
Second, exposing one layer at a time made it impossible for the excavators to assess the vertical relations that are essential to understanding the stratigraphy of the site. This serious methodological error accounts for much of the horrendous confusion that has characterized the interpretation of the site ever since.|
Nevertheless, the Oriental Institute excavators did make a number of extraordinary discoveries and identified 20 major levels from the Neolithic period (sixth millennium B.C.E.) to the Persian period (fifth century B.C.E.). 
During the 1960s and early 1970s, Yigael Yadin returned to Megiddo for three short seasons on behalf of the Hebrew University of Jerusalem. His objective was to clarify the complicated stratigraphic problems related to the remains of the Solomonic period (tenth century B.C.E.), in particular, the fortifications.  In some respects he was successful, but in others he only added to the confusion.
The mound of Megiddo itself-a modest 15 acres—rises more than 100 feet above the broad expanse of the Jezreel Valley. At various periods Megiddo was enlarged to include a lower city northwest of the tell that doubled the area of the city. The steep slopes of the mound give an indication of the massive fortifications buried inside.