A complete electronic version of Einhard's biography of Charlemagne is available through the Medieval Sourcebook. It is well known that Einhard based his text on the biographies of Roman Emperors written by Suetonius (c. 69-after 129 A.D.), especially the biography of Augustus. An electronic version of the Suetonius text is available through the Ancient Sourcebook.

The following excerpts from Einhard include underlined passages which are keyed to show the parallels in the Suetonius's text.

Charles was large and strong, and of lofty stature, though not disproportionately tall (his height is well known to have been seven times the length of his foot); the upper part of his head was round, his eyes very large and animated , nose a little long, hair fair, and face laughing and merry. Thus his appearance was always stately and dignified, whether he was standing or sitting; although his neck was thick and somewhat short, and his belly rather prominent; but the symmetry of the rest of his body concealed these defects. His gait was firm, his whole carriage manly, and his voice clear, but not so strong as his size led one to expect. His health was excellent, except during the four years preceding his death, when he was subject to frequent fevers; at the last he even limped a little with one foot. Even in these years he consulted rather his own inclinations than the advice of physicians, who were almost hateful to him, because they wanted him to give up roasts, to which he was accustomed, and to eat boiled meat instead. In accordance with the national custom, he took frequent exercise on horseback and in the chase, accomplishments in which scarcely any people in the world can equal the Franks. He enjoyed the exaltations from natural warm springs, and often practiced swimming, in which he was such an adept that none could surpass him; and hence it was that he built his palace at Aix-la-Chapelle, and lived there constantly during his latter years until his death. He used not only to invite his sons to his bath, but his nobles and friends, and now and then a troop of his retinue or bodyguard, so that a hundred or more persons sometimes bathed with him.

He used to wear the national, that is to say, the Frank, dress - next his skin a linen shirt and linen breeches, and above these a tunic fringed with silk; while hose fastened by bands covered his lower limbs, and shoes his feet, and he protected his shoulders and chest in winter by a close fitting coat of otter or marten skins. Over all he flung a blue cloak, and he always had a sword girt about him, usually one with a gold or silver hilt and belt; he sometimes carried a jewelled sword, but only on great feastdays or at the reception of ambassadors from foreign nations. He despised foreign costumes, however handsome, and never allowed himself to be robed in them, except twice in Rome, when he donned the Roman tunic, chlamys, and shoes; the first time at the request of Pope Hadrian, the second to gratify Leo, Hadrian's successor. On great feastdays he made use of embroidered clothes and shoes bedecked with precious stones, his cloak was fastened by a golden buckle, and he appeared crowned with a diadem of gold and gems, but on other days his dress varied little from the common dress of the people.

Charles was temperate in eating , and particularly so in drinking , for he abominated drunkenness in anybody, much more in himself and those of his household; but he could not easily abstain from food, and often complained that fasts injured his health. He rarely gave entertainments , only on great feastdays , and then to large numbers of people. His meals ordinarily consisted of four courses , not counting the roast, which his huntsmen used to bring in on the spit; he was more fond of this than of any other dish. While at table, he listened to reading or music. The subjects of the readings were the stories and deeds of olden time: he was fond, too, of St. Augustine's books, and especially of the one entitled The City of God. He was so moderate in the use of wine and all sorts of drink that he rarely allowed himself more than three cups in the course of a meal. In summer, after the midday meal, he would eat some fruit, drain a single cup, put off his clothes and shoes, just as he did for the night, and rest for two or three hours. He was in the habit of awaking and rising from bed four or five times during the night . While he was dressing and putting on his shoes, he not only gave audience to his friends, but if the Count of the Palace told him of any suit in which his judgement was necessary, he had the parties brought before him forthwith, took cognizance of the case, and gave his decision, just as if he were sitting on the judgement seat. This was not the only business that he transacted at this time, but he performed any duty of the day whatever, whether he had to attend to the matter himself, or to give commands concerning it to his officers.

Charles had the gift of ready and fluent speech , and could express whatever he had to say with the utmost clearness . He was not satisfied with command of his native tongue merely, but gave attention to the study of foreign ones, and in particular was such a master of Latin that he could speak it as well as his native tongue ; but he could understand Greek better than he could speak it . He was so eloquent, indeed, that he might have passed for a teacher of eloquence. He most zealously cultivated the liberal arts, held those who taught them in great esteem, and conferred great honors upon them. He took lessons in grammar from the deacon Peter of Pisa, at that time an aged man. Another deacon, Albin of Britain, surnamed Alcuin, a man of Saxon extraction, who was the greatest scholar of the day, was his teacher in other branches of learning. The King spent much time and labor with him studying rhetoric, dialectics, and especially astronomy; he learned to reckon, and used to investigate the motions of the heavenly bodies most curiously with an intelligent scrutiny. He also tried to write, and used to keep tablets and blanks in bed under his pillow, that at leisure hours he might accustom his hand to form the letters ; however, as he did not begin his efforts in due season, but late in life, they met with ill success.

He cherished with the greatest fervor and devotion the principles of the Christian religion, which had been instilled into him from infancy. Hence it was that hebuilt the beautiful basilica at Aix-la-Chapelle, which he adorned with gold and silver and lamps, and with rails and doors of solid brass.He had the columns and marbles for this structure brought from Rome and Ravenna, for he could not find such as were suitable elsewhere. He was a constant worshipper at this church as long as his health permitted, going morning and evening, even after nightfall, besides attending mass; and he took care that all the services there conducted should be administered with the utmost possible propriety, very often warning the sextons not to let any improper or unclean thing be brought into the building or remain in it. He provided it with a great number of sacred vessels of gold and silver and with such a quantity of clerical robes that not even the doorkeepers who fill the humblest office in the church were obliged to wear their everyday clothes when in the exercise of their duties. He was at great pains to improve the church reading and psalmody, for he was skilled in both, although he neither read in public nor sang, except in a low tone and with others.

He was very forward in succoring the poor, and in that gratuitous generosity which the Greeks call alms, so much so that he not only made a point of giving in his own country and his own kingdom, but when he discovered that there were Christians living in poverty in Syria, Egypt, and Africa, at Jerusalem, Alexandria, and Carthage, he had compassion on their wants, and used to send money over the seas to them. The reason that he zealously strove to make friends with the kings beyond the seas was that he might get help and relief to the Christians living under their rule. He cherished the Church of St. Peter the Apostle at Rome above all other holy and sacred places, and heaped its treasury with a vast wealth of gold, silver, and precious stones. He sent great and countless gifts to the popes, and throughout his whole reign the wish that he had nearest at heart was to reestablish the ancient authority of the city of Rome under his care and by his influence, and to defend and protect the Church of St. Peter, and to beautify and enrich it out of his own store above all other churches. Although he held it in such veneration, he only repaired to Rome to pay his vows and make his supplications four times during the whole forty-seven years that he reigned.