Charlemagne was also fond of study. He learned Latin and Greek, and improved his native German language by inventing German words for the months and the winds. He paid great attention to astronomy and music, and in theological studies evinced a strong interest. He caused to be commenced the first Germanic grammar. But with all his learning there was one thing he could not accomplish, which was to write a good hand, though he zealously practiced the art, even putting his little tablets under his pillow that he might catch at any odd moments day or night to perfect his imperfect writing. At whatever palace Charlemagne was residing, he always formed there a school called the School of the Palace, where many learned men were gathered together, and where members of the royal family, including Charlemagne himself, and his children, took lessons in the different sciences, grammar, rhetoric, and theology. Two names are famous among these wise men, who became the particular advisers and confidants of Charlemagne, Alcuin and Eginhard, who afterwards became the biographer of Charlemagne, and the adviser of his son Louis le Débonnaire. It was the custom for members of this school to assume other names than their own: thus Charlemagne was called David; Alcuin, Flaccus; Angilbert, Homer; and Eginhard, Bezaleel,—that nephew of Moses to whom God had granted the gift of knowing how to work skilfully in wood and all materials needed for the ark and tabernacle. All of these scholars afterwards became great dignitaries in the church. Charlemagne was of a cheerful disposition, and fond of hunting and other sports. He was especially expert in swimming. He sometimes played jokes upon his chiefs and nobles, and the old monks of his time tell several stories regarding his sly humor. At one time when he thought his courtiers were too much given to fine clothes, he commanded a party of them when decked out in their finest trappings, to follow him in the chase through the rain, mud, and brambles. He was of a tall figure, and though his dress was rich and gorgeous when the occasion demanded it, he was not fond of finery. His appearance is thus described by Eginhard:—