323 BC, control of the city passed to one
of his generals, Ptolemy I Soter. Ptolemy
made Alexandria the capital of Egypt,
and it soon became the most important
city in the world. Greek scholars and
scientists went there to study in its great
library. The Pharos, a lighthouse built in
Alexandrias harbor, was one of the
SevenWonders of theWorld.
Alexandria came under Roman rule in
30 BC and Arab rule in AD 642. The
Arabs built a new capital at Cairo and
neglected Alexandria. In 1517 Alexandria
was conquered again, this time by
the Turks. By the late 1700s it was just a
small fishing village. Alexandria revived
as a trade center in the 1800s after
canals were built to link the city to the
Nile River. Today Alexandria remains a
thriving port city.
#More to explore
Alexander the Great Cairo Egypt
Egypt, Ancient Nile River
Alfred the Great
More than 1,000 years ago a king
named Alfred saved part of England
from falling under the control of Denmark.
At the time, England was divided
into several small kingdoms, andWessex
was one of those. Alfred was king of
Wessex. Although the other kingdoms
fell to the Danes, Alfred keptWessex
free. One of Englands best-loved kings,
he is known as Alfred the Great.
Battles Against the Danes
Alfred was born in 849. He was the
youngest son of Aethelwulf, king of
Wessex. Alfreds older brother Aethelred
Few structures remain from Alexandrias
early history. A monument
called Pompeys Pillar and
a sphinx were once part of a
temple of a god called Sarapis.
BRITANNICA STUDENT ENCYCLOPEDIA Alfred the Great 75
became king after Aethelwulf. When
Aethelred died in 871, Alfred became
king.
Alfreds people were the Saxons. They
had come to Britain from Germany several
hundred years earlier, along with the
Angles and the Jutes. All were now
threatened by the Danes, who were
invaders from northern Europe. The
Danes were also called Vikings.
Several English kingdoms fell to the
Danes. In 871 and again between 876
and 878 AlfredsWessex forces fought
against the invaders. In the end the
Danish king surrendered to Alfred.
In 886 Alfred went beyondWessex and
freed London. All the English people
who were not ruled by Danes then
accepted him as king. Alfreds son and
grandsons eventually gained control over
all of England.
Role as a King
Alfred was not only a bold warrior. He
was also a smart organizer who knew
how to build forts, use ships, and
arrange alliances. In peace he was a wise
ruler who tried to protect the weak from
bad judges. He also gave his people better
laws.
Alfred loved learning. He read books in
Latin and hired scholars to translate
them into English. Sometimes he did
the translating himself. The Anglo-
Saxon Chronicle, a record of Englands
early history, was begun in his reign.
Alfred died in 899.
#More to explore
England Vikings
Algae
Algae are organisms, or living things,
that are found all over the world. Algae
are very important because they make
much of Earths oxygen, which humans
and other animals need to breathe.
Some algae, such as seaweeds, look like
plants. However, algae are actually neither
plants nor animals. Instead they
belong to a group of living things called
protists.
There are about 27,000 different
species, or types, of algae. They are
most common in water, such as oceans,
rivers, lakes, streams, ponds, and
marshes. Some species live in soil or on
leaves, wood, and stones. Algae even
grow on animals such as turtles and
polar bears.
Alfred the Great
76 Algae BRITANNICA STUDENT ENCYCLOPEDIA
Algae can be green, blue, red, or brown.
They vary greatly in size. Some species
are so small that they can only be seen
through a microscope. On the other
hand, the algae called kelp can reach
200 feet (60 meters) in length.
Algae differ from plants in several ways.
They do not have stems or leaves, and
their roots are different from plant roots.
Algae also do not produce flowers or
seeds, as plants do. Like plants, however,
algae make their own food through a
process called photosynthesis. Photosynthesis
also releases oxygen into the air.
In addition to making oxygen, algae are
important for other reasons.Water animals
such as whales, seals, fish, octopuses,
and starfish depend on algae for
food. People also eat some types of algae.
In many parts of the world farmers use
seaweeds as fertilizer (a material to help
crops grow).
#More to explore
Living Things Protist Photosynthesis
An alligator hides in algae-covered water.
A magnified view of red algae shows that it looks like a plant. But algae belong to a group
of living things called protists.
BRITANNICA STUDENT ENCYCLOPEDIA Algae 77
Algeria
Algeria is a country on the north coast of
Africa. It is the second largest country on
the continent. Its history, language, customs,
and Islamic religion make it a part
of the Arab world. The capital is Algiers.
Geography
Algeria is bordered by Tunisia, Libya,
Niger, Mali, Mauritania,Western
Sahara, and Morocco. The Mediterranean
Sea lies to the north.
The northern part of the country is
known as the Tell. Most of the people
live there. The Atlas Mountains separate
the Tell from the Sahara Desert, which
takes up about four fifths of the country.
The Sahara contains plateaus and large
areas of sand called ergs. It also features
Algerias highest peak, Mount Tahat,
which rises to 9,573 feet (2,918 meters).
Northern Algeria has warm, dry summers
and mild, rainy winters. The
Sahara can be very hot or quite cold,
depending on the season and time of
day. It rarely rains there.
Plants and Animals
Plants in Algeria survive without much
water. The Tell region has evergreen
shrubs and low trees. In the desert are
tufts of grass, shrubs, and acacia and
jujube trees.
Hyenas, jackals, monkeys, hawks, and
desert snakes are native to Algeria. So are
some antelope, hares, rodents, and wild
boars. Scorpions are common in the
Sahara.
People
Most Algerians have Berber or Arab
ancestors. The Berbers were the people
who lived in North Africa before the
arrival of the Arabs. Arabs now make up
more than 70 percent of the population.
Almost all Algerians are Muslim.
The Erg Admer is a large area of sand
dunes in southern Algeria.
78 Algeria BRITANNICA STUDENT ENCYCLOPEDIA
Economy
The Algerian government controls the
economy. Algerias main products are
petroleum (oil) and natural gas. However,
most Algerians work in the government,
the military, or in agriculture.
Crops include wheat, potatoes, tomatoes,
barley, dates, onions, oranges,
olives, and grapes. Sheep and goats are
the main livestock. Manufacturers make
food and tobacco products; cement,
bricks, and tiles; and iron and steel
products.
History
Mainly Berbers lived in ancient Algeria.
Waves of invadersPhoenicians,
Carthaginians, Romans, and Vandals
conquered them at different times. Muslim
Arabs invaded in the 600s and 700s.
The Turkish Ottoman Empire gained
control of northern Algeria in 1518.
France invaded in 1830 and made Algeria