Because of the extravagant biography of Rollo written a century later by Dudo of Saint-Quentin, it sometimes seems that we know him fairly well. In fact, although in Dudo's time Rollo was remembered as the founder of the Norman dynasty, the fact is that during his own lifetime, he was a virtual non-entity. Although Dudo says much about his career prior to 911, virtually every story he tells is an obvious borrowing from the adventures of other Northmannic leaders told in tenth-century Frankish chronicles, and the rest are obvious legends. Dudo's account contains not a single verifiable fact about Rollo. The "Founder of Normandy" also is never mentioned in any contemporary source before 911, and in fact the "Treaty of Saint-Clair-sur-Epte," made so famous by Dudo's story of the Norman upending Charles the Simple instead of stooping to kiss his foot, also made no impact whatsoever on the writers of the time. Only three brief mentions of Rollo occur in contemporary sources, and it is upon these mentions that we must build what little image of him we can manage.
The first contemporary mention of Rollo is in a charter of King Charles Simplex in 918. Here, Charles grants the lands of an abbey "except for the part that we have given to the Northmen of the Seine, namely to Rollo and his companions." At roughly the same time, the Frankish historian Flodoard of Reims wrote: "After the war that Count Robert waged against the Northmen at Chartres, certain maritime pagi, along with the city of Rouen (which they had nearly destroyed) and other pagi which were subjected to it, were conceded to them, and they agreed to take up the faith of Christ." At some point before 928, the archbishop of Rouen wrote to Herveus, archbishop of Reims, asking for advice on how to handle lapsed pagan converts. Herveus in turn wrote to Pope John X, asking "What should be done when they have been baptized and rebaptized, and after their baptism continue to live in pagan fashion, and in the manner of pagans kill Christians, massacre priests, and offering sacrifices to idols, eat what has been offered?" It is also perhaps significant that in a poem mourning the death of Rollo's son, William Longsword, William is called the Christian son of a pagan father, although this might have been a rhetorical reference to Rollo's earlier life.
Thus it seems that after the Battle of Chartres, which most historians date to 911 and at which a large Northmannic force was soundly defeated, King Charles granted some land around Rouen and to the sea to Rollo and his companions, who converted to Christianity but, at least in some cases, quickly reverted to paganism in a fairly definitive manner. A number of important points should be made. First, there is no indication that Rollo was involved with the Battle of Chartres. Dudo later says that he in fact led the Northmannic army there, but then Dudo says that Rollo led every major Northmannic force in France, and some in England; it seems to be his way of making somebody important out of a man who left virtually no trace in the historical record. Charles' motivation seems to have been to cut off future attacks on the Seine and its tributaries by giving those Northmen who already controlled Rouen, the first major city on the Seine, formal recognition in exchange for their blocking access to other Northmannic forces.
Second, it is not clear exactly which lands Rollo and his companions received, but it would seem to have been roughly the Roumois and the Pays de Caux. Some historians, believing that the concession of Charles Simplex and two further "grants" (which I will come to shortly) comprised a formal concession of the future Normandy, have drawn neat maps dividing Normandy into three parts, and thus made the first concession cover all of Normandy east of the Risle, plus the entire Pays d'Ouche, but there is no evidence that Charles had such a great extent in mind. And third, the territory controlled by Rollo by no means contained the only Northmannic settlements in the future Normandy; we know from place-names that the Northmannic presence was especially strong not only in the Pays de Caux and Roumois, but also in the Bessin and the entire Cotentin peninsula. These Northmen of western Northmanland, at least to begin with, had no connection with the Northmen of Rouen.
So far we have a group of Northmen, led by Rollo, occupying Rouen and its environs with the permission of King Charles, and at least nominally Christianized but subject to spectacular reversions. In the following years, while the sources are silent on events within the newborn Rollonid Principality, the Carolingian political landscape was changing dramatically. During the 910s, Charles managed to alienate many of his nobles through various actions, especially in Lotharingia; these events inspired Henry I, king of the East Franks, to renew East Frankish claims to Lotharingia, and Robert of Neustria, brother of King Odo, to lead a revolt against Charles. For several years the struggle continued, culminating in 922 when Charles fled his kingdom and Robert was crowned king. In the following year, Charles returned with an army; in the ensuing battle Robert was killed, but his son Hugh the Great (now so-called to distinguish him from his son, Hugh Capet) and Herbert II of Vermandois defeated Charles. The events that followed are somewhat fuzzy, but apparently neither Hugh nor Herbert would allow the other to become king, so they settled on Ralph, the son-in-law of King Robert and the duke of Burgundy. Possibly they believed that as a relative outsider to the West Frankish world, he would be easier to control. Herbert then arranged a meeting with Charles, arrested him, and threw him into captivity for the rest of his life (he died in 929). His possession of the Carolingian claimant to the throne only enhanced his power, as did his arrangement in 925 for his five-year-old son Hugh to be made archbishop of Reims, at the time the spiritual capital of the West Frankish realm. One may assume that the new archbishop was somewhat subject to Herbert's influence.
To pick up the scanty narrative of events in the Rollonid Principality from contemporary sources, in 924 Flodoard reports: "The Northmen entered peace with the Franks through the oaths of Counts Hugh [the Great] and Herbert [of Vermandois] and also Archbishop Seulf [of Reims], in the absence of King Ralph; but with Ralph's consent the lands of Maine and the Bessin were conceded to them in the peace-treaty." The neat, three-part maps of Normandy make this concession cover all the lands between the Vire and the Risle, and usually claim that Maine was a mistake, since it does not lie within Normandy and was never claimed by the Rollonids until well into the eleventh century. But seen in the light of previous "grants" by Frankish kings to Northmen, this should be seen not as a transfer of clearly-defined territory from one party to the other, but rather as permission by the king for Rollo and his companions to take whatever control they can over lands that have slipped completely out of the king's power; in other words, trying to replace "bad" Northmen (i.e., ones with whom the king has no relationship) with "good" ones (with whom he does). We can tell from the very existence of this treaty that the Northmen of Rouen had fallen out with the king since the initial concession, and now were being reconciled. But the reconciliation did not last, for Flodoard informs us in 925 that an army of Northmen of Rouen moved east, plundering Beauvais, Amiens and Noyons. At the same time, the Frankish natives of the Bessin rose against the Northmen there, and a Frankish army led by Hugh the Great's men ravaged the Roumois. The Northmannic army quickly returned home, just in time to face a new invasion of Herbert of Vermandois and Arnulf of Flanders, along with the count of Ponthieu (along the coast bordering Eastern Northmanland, centered on Montreuil). They besieged the Northmannic stronghold of Eu, and despite a large relief force from Rouen led by Rollo (this is the second time he is mentioned by a contemporary source), they succeeded in capturing and destroying it. But the hostilities seemed to end there, for the moment.
The final years of Rollo are very shadowy, although he seems to have played some role in Frankish politics. In 927, a war broke out between King Ralph and Herbert of Vermandois; when Ralph had returned to Burgundy to see to his duties there, Herbert apparently began to float the idea of a restoration of Charles Simplex. He brought Charles to meet with the Northmen (presumably led by Rollo) at Eu, where "the son of Rollo [i.e., William Longsword] committed himself to Charles and confirmed friendship with Herbert." Apparently at this time, Herbert's son Odo was left with Rollo as a hostage. This was a normal component of peace treaties during this period; the hostages were treated honorably, and in addition to serving as incentive for the parties to behave (in extreme cases, hostages could be executed for bad behavior on the other side's part), they also served to create a closer relationship between the sides. Flodoard does not explain why this meeting took place, or what the participants expected to accomplish. In the following year, however, Herbert and Ralph were reconciled; but Rollo did not return Odo to his father until Herbert committed himself to Charles Simplex. (Flodoard's account of this is the third and final time Rollo is mentioned in contemporary accounts.) It would seem that Rollo, once he had allied himself with Charles, refused to accept Herbert's change of heart, and forced Herbert to renew his own alliance with Charles. It should also be noted that Rollo owed his original entré into Frankish politics to Charles, and that he had never met Ralph (the "grant" of 924 was made on Ralph's behalf, but in his absence). In the event, however, nothing came of this uneasy alliance among Rollo, Herbert, and Charles, since Charles died in 929.
We do not know when Rollo died, but it must have been sometime between 928, when Flodoard last mentions him, and 933, when William Longsword makes his first appearance as the Rollonid ruler. We may suspect, however, that Rollo played a greater part in the Frankish world than this bare narrative of his career has shown; a later source calls him a friend of William of Aquitaine, and the fact that William married Rollo's daughter lends credence to this story. But overall, Rollo died in much the same obscurity in which he lived; although in retrospect his achievement as founder of Normandy seems considerable, in his own day he was simply a Northmannic leader who got some territorial concessions from the Frankish king. The Rollonid Principality on the death of its founder was a small area centered upon Rouen, surrounded by neighbors hungry to reclaim what had been lost to the foreigners, and allied with the king who was losing the Frankish civil war; its future was still very much in doubt.