Theoretically, the Byzantine Emperor was, just like in the times of the Roman Empire, chosen on the basis of his personal qualities and merits — by the grace of God, of course. Practically, the factors which determined the ascension of a person to the throne were much more complex, the methods of gaining power being multifarious. In consequence, the political philosophy was confronted with the question of whether it is virtue (aretç) or origin (génoz) that defines an Emperor. Independently of this rather theoretical question, however, and despite the claims that the personal qualities are decisive in the choice of the Emperor, the origin of the ruler played an important role in the consciousness of the Byzantines of all epochs. This is why great attention was paid to the creation of family trees, especially in the cases when the Emperor was of low origin (homo novus) or when it was for some reason necessary to strengthen his legitimacy. The choice of the genealogy was not random: since it carried a clear political message, it was of utmost importance with whom the Emperor in power would be associated and whose historical deeds or legendary personality would serve as a moral model. Also important is the fact that the search of a "good family" was as a rule triggered by the need to confirm one's own virtue. Thus, genealogies often reflect a certain system of values, usually emphasizing morality, courage in war, care for the welfare of the country, piety, etc. The choice of the archetype depended, of course, on the needs of the ruler for whom the genealogy was created. All this allows us to consider legendary genealogies as an expression of the imperial ideology. Notwithstanding their chronological diversity, the Byzantine imperial genealogies display very similar characteristics, i.e. they contain stereotypical elements, many of which had been established already in the first centuries of the Eastern Empire. In the early Byzantine period, when Christianity was still young, Emperors were frequently associated with pagan gods and semi gods, like Jupiter, Mars or Hercules. The Roman tradition of the eastern part of the Empire is also reflected in the fictive genealogies, so that the Emperors often chose Western Emperors or illustrious personalities and families of the Republican Era as their ancestors. The convention of establishing genealogical relations with the past rulers or their families (e.g. Claudius Gothicus, Trajan, the Flavii) served on one hand to create the impression of continuity and legitimacy, and on the other, to affirm the proclaimed system of values, since individual Roman Emperors had by that time become the prototypes of certain values (so Nerva stood for tranquility, Titus for philanthropy, Antoninus for high morality, Hadrian for justice and legality, Trajan for a successful military leader). In the same fashion, the creation of the family ties with persons from the Roman republican past, like the members of the family of the Scipios or Gnaeus Pompeius, was instrumental in the emphasizing of not only noble origin but also virtue. Interestingly enough, whereas the bonds with the Roman state are permanently evoked, the exempla from the Greek history play only a minor role in legendary genealogies (mostly Corinthians and Spartans, sometimes even mythical nations, like Homer's Pheacians). The central position of the Roman ideology is also reflected in the tendency to establish direct geographical connections between the origin of the ruler and either Rome itself or one of the Western provinces, so that the motif of migration is often found in the genealogies. On the other hand, Byzantine writers sometimes tended to boast with their knowledge of the history of the Ancient Orient, connecting famous personalities (like Artaxerxes) or dynasties (Achaemenids, Arsacids) with the Emperor whose genealogy they were composing. A special place in legendary genealogies is occupied by Constantine the Great. Almost as a rule, the genealogies postulate a kinship with him, often confirming it with the alleged physical resemblance. Depending on the purpose of the genealogy, certain purported features of Constantine's character were emphasized, so that he is alternately mentioned as a protector of the Christian faith, a triumphant military leader, or as a wise administrator of the Empire. Apart from that, the motifs of founding the new Capital and the migration of the Roman patrician families to Constantinople represent important topoi in this literary genre. The two most fascinating specimens of legendary genealogies in the Byzantine literature — those of Basil I the Macedonian and Nikephoros III Botaneiates — show that the choice of the elements of which the genealogy is composed (personality, family, dynasty) is at the same time a strong indication of the reason why it was composed in the first place. The genealogy of Basil the Macedonian was doubtlessly conceived by more than one person. It is quite certain that the idea to compose it originally came from Photios and was taken over by Basil's descendents — his son Leo VI and his grandson Constantine VII Porphyrogennetos. The core of Basil's legendary genealogy is the story of his origin from the Parthian-Armenian dynasty of Arsacids (an indication of the Armenian origin of the founder of the Macedonian dynasty?). Constantine Porphyrogennetos elaborated this story further, describing in some detail the fate of Arsac's descendents, to whom Basil was allegedly related on his father's side, in the Byzantine Empire. This, of course, does not mean that he forgot to create connections between his grandfather and the standard legendary ancestors, like Constantine the Great (on Basil's mother's side) and Alexander the Great (the common ancestors of both Basil's parents). This apocryphal family tree certainly has its roots in the fact that the founder of the Macedonian dynasty was a parvenu of low origin, whose ascent to the throne was maculated by the murder of his predecessor and benefactor Michael III: apart from providing Basil with the noble origin, the genealogy was supposed to strengthen his right to the crown. One should keep in mind, though, that Basil's genealogy was written in the time of "Macedonian renaissance", so that its content is doubtlessly partly a product of the erudition of the compilers. In the course of time, legendary genealogies were enriched with new elements, stemming from the Byzantine history in the narrower sense of the word. The genealogy of Nikephoros III Botaneiates, compiled by Michael Attaleiates in the second half of the 11th century, is a good illustration to this. In contrast to Basil the Macedonian's genealogy, it is interwoven with real historical data, so that it cannot be called 'legendary' in its entirety. It would probably be more appropriate to call it a genealogy of both the Phokades and the Botaneiatai, since its core is made up of an invented story of the origin of the famous Byzantine family of Phokades, from which the family of Botaneiatai purportedly stems. The genealogy is clearly divided into three parts. In the first part, Attaleiates develops a theory according to which the Phokades are descendents of the Roman patrician families of Fabii and Scipios. The second part is devoted to the elaboration of the genealogical connection between the Phokades and the Botaneiatai, a tour deforce achieved by the claim that the latter are direct descendents of Nikephoros II Phokas, who is not only the central figure of this part in his capacity as an ancestor of Nikephoros III, but also as a model of a virtuous Emperor. Comparable to the habit of other writers to single out one or another characteristic trait of Constantine the Great according to their needs, Attaleiates concentrates on Nikephoros Phokas' military qualities, which are similar to those possessed by his "descendent" Botaneiates, and emphasizes the physical resemblance between the two rulers. In all likelihood, the part on the genealogy of the Phokades, as well as the story of Nikephoros Phokas, were taken over from an earlier tradition dealing with this renowned family, which Attaleiates implicitly mentions when he says that he had used 'an old book' and some other writings. As indicated above, the last, third, part of the genealogy, devoted to the deeds of Nikephoros Botaneiates' father and grandfather, does not fit the narrow definition of a legendary genealogy, despite the exaggerations Attaleiates uses in order to satisfy the demands of the genre. The description of Nikephoros Botaneiates' family tree represents merely an excursus within Attaleiates' History, but its composition has nevertheless an internal coherence and logic. Namely, all parts of the genealogy (the histories of the Fabii/Scipios, Phokades, and Botaneiatai) have one characteristic in common: the stories of the military deeds of the members of these families are used as an illustration of the military virtues of Nikephoros III. Since the hidden intention of the panegyric for Nikephoros III Botaneiates is to justify his usurpation of the throne, it is clear that a genealogy in this form — especially the section pertaining to Nikephoros Phokas and his kinship with the usurper's father and grandfather — represents a good basis for a legalistic interpretation of the coup d'état of 1078. The permeation of legendary genealogies with the Byzantine history is not confined only to individual Emperors which, like Nikephoros II Phokas, get assigned the role of the ancestor and moral model: some aristocratic families, most often the Phokades and the Doukai, also became moral exempla, serving to prove the reputation and the nobility of the ruler. As in the case of the Phokades, there is also a legendary tradition surrounding the family of Doukai, which made them a kind of model family: Being related to them became a measure of nobility, since it allowed the less prominent families to occupy a more distinguished place on the hierarchy of the Byzantine nobility. The prominence certain family names achieved — mostly those of the families which created a dynasty — led from the beginning of the 12th century until the fall of the Empire to free adoption and combination of more different surnames (mostly Doukai, Komnenoi, Angeloi, Palaiologoi, Kantakouzenoi, etc.). This, in turn, led to the creation of fictitious family trees. This kind of apocryphal construction of one's own origin was characteristic not only of the Byzantine culture but rather represented a very common phenomenon in the medieval world. In the medieval Serbia, for instance, its dissemination was fostered by the translation of the writings of the Byzantine chroniclers (Georgios Monachos, John Malalas, Constantine Manasses, and John Zonaras), so that legendary genealogies, written according to the Byzantine pattern, became an expression of the wish to include one's own history into the flow of the world history. Finally, a note on the reception of this genealogical line of thought. Parallel to the fictitious genealogies, there also existed a consciousness about them: Just like the development and the functional load of genealogies reveals a lot about the attitudes of the Byzantines towards power, so do the Byzantine writers who often criticize and ridicule the genealogies of individual Emperors. .
