of eastern Greece, many of the Aegean
islands, and the Ionian coast in Asia
Minor. The Spartans thought that Athens
was too powerful. They began the
PeloponnesianWar against Athens in
431 BC.
At first, the Athenians avoided battle on
land. They stayed within the walls of
their city. Their navy attacked Sparta
from the sea. The Athenians stayed safe
until 430 BC, when plague (a deadly
disease) broke out in the city. The disease
killed one quarter of the people,
including Pericles, their leader.
Sparta won the war in 404 BC. Sparta
kept a leading position for only 30 years,
however. In 371 BC another Greek city,
called Thebes, defeated Sparta.
Rise of Macedonia
In the 300s BC Macedonia, a kingdom
to the north, gained strength. The
Macedonians were distantly related to
the Greeks. The Macedonian king Philip
II conquered the Greek city-states by
338 BC. When he died in 336, his son
Alexander came to power.
Alexander, called Alexander the Great,
was a military genius. First he defeated
the Persian king Darius III in 333 BC.
Then he spent a decade conquering
lands from Egypt to India. He took
Greek civilization to much of the
ancient world.
The Hellenistic Age
Alexander died in 323 BC. The period
following his death is called the Hellenistic
Age. “Hellenistic” means “Greeklike.”
Alexander’s empire broke into three
main kingdoms in Macedonia, Egypt,
and the Middle East. In these kingdoms,
Greek culture mixed with local cultures.
In Greece itself, some of the cities
regained their independence or joined
together in leagues.
Ancient Rome conquered all of Greece
and the three Hellenistic kingdoms by
30 BC. Greece remained under the
One of the last
of the Hellenistic
rulers was
Cleopatra,
queen of
Egypt.
A sculpture from about 320 BC
shows a young woman of the
Hellenistic Age of ancient Greece.
156 Greece, Ancient BRITANNICA STUDENT ENCYCLOPEDIA
Roman Empire until AD 395. Then it
became a part of the Byzantine Empire.
#More to explore
Aegean Civilization • Alexander the
Great • Athens • Homer • PersianWars
• Sparta
Greek Orthodox
Church
#see Eastern Orthodox Churches.
Greenhouse
Effect
The greenhouse effect is a warming of
Earth’s surface and the air above it. It is
caused by gases in the air that trap
energy from the sun. These heattrapping
gases are called greenhouse
gases. The most common greenhouse
gases are water vapor, carbon dioxide,
and methane.Without the greenhouse
effect, Earth would be too cold for life
to exist.
Land, oceans, and plants absorb, or soak
up, energy from sunlight. They release
some of this energy as heat. Greenhouse
gases absorb the heat and then send it
back toward Earth.Without greenhouse
gases, this heat would escape back into
space.
Scientists believe that human activities
are increasing the greenhouse effect.
When people drive a car or operate a
factory they burn coal, oil, and other
fossil fuels. This adds extra greenhouse
gases to the air, and the extra gases trap
more heat. Many scientists think that
this has led to global warming, or a
steady rise in the average temperature of
Earth’s surface.
#More to explore
Air • Earth • Fossil Fuel • Global
Warming
Greenland
Greenland is the world’s largest island. It
lies in the very cold northern part of the
world. Greenland belongs to Denmark.
The capital and largest town is Nuuk.
Geography
Greenland is in the northern Atlantic
Ocean. The northern tip is less than 500
miles (800 kilometers) from the North
Pole. A massive ice sheet, or glacier, cov-
Greenland
never was
very green.
Erik the Red
gave that
name to the
island because
he wanted
people to
move there.
Energy from the sun heats Earth’s surface
and atmosphere. Greenhouse gases keep
much of this heat from reflecting back into
space.
BRITANNICA STUDENT ENCYCLOPEDIA Greenland 157
ers most of Greenland. At its deepest
point the ice is 10,000 feet (3,000
meters) thick. Mountains run along the
island’s east and west coasts. The coastline
is indented in many places by narrow
strips of sea, which are called fjords.
People
The people of Greenland are mostly of
Inuit (Eskimo) origin. Many of them
also have some European roots. Most of
the rest of the people are Danish (from
Denmark). The main languages are
Greenlandic (an Inuit language), Danish,
and English. Almost everyone lives
in small towns along the coast.
Economy
Greenland relies on financial aid from
the Danish government. The island’s
economy also depends on fishing. The
part of the land that is not covered in ice
is used mainly to raise sheep and reindeer
for meat, milk, and wool. In the
north people hunt seals, polar bears, and
foxes for their meat and skin.
History
The Inuit probably crossed from North
America to northwestern Greenland
between 4000 BC and AD 1000. In AD
986 Erik the Red, a Viking from Norway,
started a colony on Greenland. The
colony lasted until the 1400s. No other
Europeans lived on Greenland until the
1700s. In 1721 the combined kingdom
Greenland does not have many roads. Many people travel by dogsled.
158 Greenland BRITANNICA STUDENT ENCYCLOPEDIA
of Norway and Denmark started a new
colony. After the union of Norway and
Denmark ended in 1814, Denmark kept
