The Alexiad by Anna Comnena is in Late Medieval Books.
This Robert was Norman by descent, of insignificant origin in temper tyrannical, in mind most cunning, brave in action, very clever in attacking the wealth and substance of magnates, most obstinate in achievement, for he did not allow any obstacle to prevent his executing his desire. His stature was so lofty that he surpassed even the tallest, his complexion was ruddy, his hair flaxen, his shoulders were broad, his eyes all but emitted sparks of fire, and in frame he was well-built where nature required breadth, and was neatly and gracefully formed where less width was necessary. So from tip to toe this man was well-proportioned, as I have repeatedly heard many say. Now, Homer says of Achilles that when he shouted, his voice gave his hearers the impression of a multitude in an uproar, but this man's cry is is said to have put thousands to flight. Thus equipped by fortune, physique and character, he was naturally indomitable, and subordinate to nobody in the world. Powerful natures are ever like this, people say, even though they be of somewhat obscure descent.
Book 4. War with the Normans.
[18th October 1081] Then after a little preliminary skirmishing on either side, as Robert was leisurely following his men, and the distance between the armies was by now fairly short, some infantry and cavalry belonging to Amicetas' phalanx dashed out and attacked the extremities of Nabites' line. These however, resisted the attack very stoutly, so the others turned their backs (since they were not all picked men), threw themselves into the sea, and up to their necks in water, made their way to the Roman and Venetian ships and begged them for protection, which they did not receive. And now, as rumour relates, directly Gaïta, Robert's wife (who was riding at his side and was a second Pallas, if not an Athene) saw these soldiers running away, she looked after them fiercely and in a very powerful voice called out to them in her own language an equivalent to Homer's words, "How far will ye flee? Stand, and quit you like men!" And when she saw they continued to run, she grasped a long spear and at full gallop rushed after the fugitives; and on seeing this they recovered themselves and returned to the fight. Meanwhile the axe-bearing barbarians and their leader Nabites had in their ignorance and in their ardour of battle advanced too quickly and were now a long way from the Roman lines, burning to engage battle with the equally brave Franks, for of a truth these barbarians are no less mad in battle than the Franks, and not a bit inferior to them. But they were already tired out and breathless, Robert noticed, and naturally so he thought, considering their rapid advance, their distance from their own lines and the weight of their weapons, and he ordered some of the foot to make a sudden attack on them. The barbarians having been previously wearied out, proved themselves inferior to the Franks, and thus the whole corps fell; a few escaped and took refuge in the chapel of Michael, the 'Captain of the Host,' as many as could crowded into the chapel itself, and the rest climbed on to the roof, being likely in this way, they imagined, to ensure their safety. But the Latins started a fire and burnt them down, chapel and all. Meanwhile the rest of the Roman army fought on bravely. But Robert like a winged horseman, dashed with his forces against the Roman phalanx, drove it back and split it up into several fragments. Consequently some of his opponents fell fighting in this battle, and others ensured their own safety by flight. But the Emperor Alexius stood fast like an impregnable tower, although he had lost many of his comrades, men pre-eminent for their birth or military skill. For instance, Constantius fell there, the son of the ex-Emperor, Constantine Ducas, not born while his father was still a private man, but born and reared in the purple and deemed worthy formerly by his father of the royal fillet. There fell too Nicephorus by name, but nicknamed Synadenus, a brave and very handsome man who strove to surpass all in fighting on that day. With him the aforementioned Constantius had often spoken about marrying his sister. Nay, Nicephorus the father of Palaeologus, and other well-known men fell too, and Zacharias received a blow in the chest which cost him his life. Aspietes and many other picked men also perished. The battle did not come to an end because the Emperor still maintained his resistance, therefore three of the Latins, one of whom was Amicetas already mentioned, the second Peter, son of Aliphas, as he himself asserted, and a third, not a whit inferior to these two, took long spears in their hands and at full gallop dashed at the Emperor. Amicetas missed the Emperor because his horse swerved a little; the second man's spear the Emperor thrust aside with his sword and then bracing his arm, struck him on the collarbone and severed his arm from his body. Then the third aimed straight at his face, but Alexius being of firm and steadfast mind was not wholly dismayed, but with his quick wit grasped in the flash of an instant the thing to do, and when he saw the blow coming, threw himself backwards on to his horse's tail. Thus the point of the spear only grazed the skin of his face a little and then, hitting against the rim of the helmet, tore the strap under the chin which held it on and knocked it to the ground. After this the Frank rode past the man he thought he had hurled from his horse, but the latter quickly pulled himself up again in his saddle and sat there calmly without having lost a single weapon. And he still clutched his naked sword in his right hand, his face was stained with his own blood, his head was bare, and his ruddy, gleaming hair was streaming over his eyes and worrying him, for his horse in its fright spurned the reins and by its jumping about tossed his curls in disorder over his face; however, he pulled himself together as much as possible and carried on his resistance to his foes. Soon however he saw the Turks fleeing and Bodinus, too, retreating without having fought at all. This ally had donned armour and arranged his army in battle-order and hovered about throughout the day as if to succour the Emperor, if need be, according to their mutual agreement; but evidently he was watching, purposing to help in the attack on the Franks if he saw victory incline to the Emperor; or, in the contrary case, to keep quite still and then beat a retreat. This being his intent, as events proved, directly he perceived that the Franks had gained a complete victory, he rode off home without having struck a single blow. The Emperor, seeing this and not finding any one to help him, turned his back upon the foe and fled. Thus did the Latins beat the Roman army.
[17th July 1085] As for Robert [aged 70] (for my tale must return to the point where it digressed and be kept within the bounds of historical narration) he did not rest even after this defeat. But as he had already sent one ship with his son to Cephalenia as he wished to take possession of the town on it, he brought his remaining ships, with the whole army, to anchor near Boditza and himself sailed for Cephalenia in a galley with one bank of oars. And before he could join his son and the rest of his forces, whilst he was lingering near Ather (which is a promontory of Cephalenia) he was seized with a violent fever. As he could not bear the burning of the fever, he asked for cold water. His men dispersed in various directions to seek water when a native said to them, "You see the island there, Ithaca. On that a large town was built long ago called Jerusalem, and now it has fallen into ruins from age; in that town there was a spring whose water was always fit for drinking and very cold." Robert was overcome with fear on hearing this for by connecting Ather and the town of Jerusalem he understood that his death was imminent. For many years before some soothsayers had prophesied to him the kind of thing flatterers are wont to tell princes, As far as Ather you shall bring all countries under your sway, but from there you shall depart for Jerusalem and pay your debt to nature." Whether the fever killed him or whether he died of pleurisy, I have no means of saying for certain. At all events he died in six days. His wife Gaïta [aged 45] reached him just in time to see him die and his son weeping over him. News of this calamity was, then sent to the son whom Robert in his lifetime had already designated heir to his dukedom. On hearing the sad tidings he was overcome at first by uncontrollable grief, but soon summoning reason to his aid and collecting himself, he sent for all his followers and, whilst weeping inconsolably for his father, he told them what had happened, and then [148] made them take the oath of allegiance to himself. Next he crossed with them all to Apulia. During the crossing he was caught in such a severe storm, although it was summer, that some of the ships were wrecked, and others dashed on the shore and beaten to pieces. The ship carrying the corpse was also half wrecked and the crew only just managed to save the coffin, and convey it safely to Venusia. Robert was buried in the old monastery dedicated to the Holy Trinity, where his brothers had been buried before him. Robert died in the twenty-fifth year of his reign as duke and at the age of seventy. The Emperor, on hearing of Robert's sudden death, was greatly relieved by having such a burden lifted from his shoulders; and very quickly turned his attention to the Normans who were still in possession of Dyrrachium. He aimed at sowing dissension amongst them by letters and other devices, as he thought that would be the easiest means of regaining the city. He also persuaded the Venetians who happened to be in the capital to advise the Venetians, Amalfians and other foreigners who were in Epidamnus to submit to his will and surrender Dyrrachium to him. And he himself did not cease making promises and offering bribes with a view to their surrendering Dyrrachium. to him. The Latins allowed themselves to be persuaded (for their whole race is very fond of money and quite accustomed to selling even their dearest possessions for an obol) and with high hopes in their hearts they formed a conspiracy and first of all slew the man who had originally suggested betraying the fort to Robert, and next his fellow-conspirators; and then they went to the Emperor, and handed over the fort to him and in return received immunity of every kind from him.