When Harun was not quite twenty-one years old he became caliph.

He began his reign by appointing very able ministers, who carried on the work of the government so well that they greatly improved the condition of the people.

Harun built a palace in Bagdad , far grander and more beautiful than that of any caliph before him. Here he established his court and lived in great splendor, attended by hundreds of courtiers and slaves.

He was very anxious that his people should be treated justly by the officers of the government; and he was determined to find out whether any had reason to complain. So he sometimes disguised himself at night and went about through the streets and bazaars, listening to the talk of those whom he met and asking them questions. In this way he learned whether the people were contented and happy, or not.

In those times Bagdad in the east and the Mohammedan cities of Spain in the west were famed for their schools and learned men. Arabian teachers first introduced into Western Europe both algebra and the figures which we use in arithmetic. It is for this reason that we call these figures the "Arabic numerals."

Harun-al-Rashid gave great encouragement to learning. He was a scholar and poet himself and whenever he heard of learned men in his own kingdom, or in neighboring countries, he invited them to his court and treated them with respect.

The name of Harun, therefore, became known throughout the world. It is said that a correspondence took place between him and Charlemagne and that, as you have learned, Harun sent the great emperor a present of a clock and an elephant.

The tribute of gold that the Empress Irene agreed to pay Harun was sent regularly for many years. It was always received at Bagdad with great ceremony. The day on which it arrived was made a holiday. The Roman soldiers who came with it entered the gates in procession. Moslem troops also took part in the parade.

When the gold had been delivered at the palace, the Roman soldiers were hospitably entertained, and were escorted to the main gate of the city when they set out on their journey back to Constantinople .

In 802 Nicephorus (Ni-ceph'-o-rus) usurped the throne of the Eastern Empire . He sent ambassadors with a letter to Harun to tell him that the tribute would no longer be paid. The letter contained these words:

"The weak and faint-hearted Irene submitted to pay you tribute. She ought to have made you pay tribute to her. Return to me all that she paid you; else the matter must be settled by the sword."

As soon as Harun had read these words the ambassadors threw a bundle of swords at his feet. The caliph smiled, and drawing his own sword, or cimeter (sim'-e-ter), he cut the Roman swords in two with one stroke without injuring the bald, or even turning the edge of his weapon.

Then he dictated a letter to Nicephorus, in which he said:

"Harun-al-Rashid, Commander of the Faithful to Nicephorus, the Roman dog: I have read thy letter. Thou shalt not hear, thou shalt SEE my reply."

Harun was as good as his word. He started that day with a large army to punish the emperor. As soon as he reached Roman territory he ravaged the country and took possession of everything valuable that he found. He laid siege to Heraclea (Her-a-cle'-a), a city on the shores of the Black Sea , and in a week forced it to surrender. Then he sacked the place.

Nicephorus was now forced to agree to pay the tribute. Scarcely, however, had the caliph reached his palace in Bagdad when the emperor again refused to pay.

Harun, consequently, advanced into the Roman province of Phrygia , in Asia Minor , with an army of 15, 000 men. Nicepherus marched against him with 125, 000 men. In the battle which followed the emperor was wounded, and 40, 000 of his men were killed.

After this defeat Nicephorus again promised payment of the tribute, but again failed to keep his promise.

Harun now vowed that he would kill the emperor if he should ever lay hands upon him. But as he was getting ready to march once more into the Roman provinces a revolt broke out in one of the cities of his own kingdom; and while on his way to suppress it the great caliph died of an illness which had long given him trouble.

Egbert the Saxon lived at the same time as did Harun-al-Rashid and Charlemagne. He was the first king who ruled all England as one kingdom. Long before his birth the people who are known to us as Britons lived there, and they gave to the island the name Britain .

But Britain was invaded by the Romans under Julius Cesar and his successors, and all that part of it which we now call England was added to the Empire of Rome. The Britons were driven into Wales and Cornwall , the western sections of the island.

The Romans kept possession of the island for nearly four hundred years. They did not leave it until 410, the year that Alaric sacked the city of Rome . At this time the Roman legions were withdrawn from Britain .

Some years before this the Saxons, Angles and Jutes, German tribes, had settled near the shores of the North Sea . They learned much about Britain ; for trading vessels, even at that early day, crossed the Channel. Among other things, the men from the north learned that Britain was crossed with good Roman roads, and dotted with houses of brick and stone; that walled cities had taken the place of tented camps, and that the country for miles round each city was green every spring with waving wheat, or white with orchard blossoms.

After the Roman legions had left Britain , the Jutes, led, it is said, by two great captains named Hengist and Horsa, landed upon the southeastern coast and made a settlement.

Britain proved a pleasant place to live in, and soon the Angles and Saxons also left the North Sea shores and invaded the beautiful island.

The new invaders met with brave resistance. The Britons were headed by King Arthur, about whom many marvelous stories are told. His court was held at Caerleon (car'-le-on), in North Wales , where his hundred and fifty knights banqueted at their famous "Round Table."

The British king and his knights fought with desperate heroism. But they could not drive back the Saxons and their companions and were obliged to seek refuge in the western mountainous parts of the island, just as their forefathers had done when the Romans invaded Britain . Thus nearly all England came into the possession of the three invading tribes.

Arthur and his knights were devoted Christians. For the Romans had not only made good roads and built strong walls and forts in Britain , but they had also brought the Christian religion into the island. And at about the time of the Saxon invasion St. Patrick was founding churches and monasteries in Ireland , and was baptizing whole clans of the Irish at a time. It is said that he baptized 12, 000 persons with his own hand. Missionaries were sent out by the Irish Church to convert the wild Picts of Scotland and at a later day the distant barbarians of Germany and Switzerland .