I confess I haven?t read all of the arguments here in detail, but I would like to make a few points on the debate.First of all, I would simply like to say how much I appreciate the respect and patience with which Ivkho has been treated, despite the contrary arguments presented against him. As a Bulgarian myself (who doesn?t live in Bulgaria), I am truly aware of the ignorance and complacency to which Westerners are prone, when it comes to discussing historical controversies involving the significant contributions of smaller countries of the present (some of which, in their heyday were playing ?in the majors? so to say from a political and military point of view). Bulgaria is undoubtedly one of those countries. Now, leaving the 717-718 siege of Constantinople aside for a moment here, I would like to point out that even prior to it, Khan Tervel had already won his place in history with being the first foreign ruler in Byzantine history to receive the prestigious title of ?Caesar?(second only to the actual Emperor), bestowed on him by the newly instated  Justinian II. This is an unprecedented episode in the history of the Eastern Roman Empire. What makes it even more impressive is the fact that Tervel was merely the second ruler of the newly founded Danube Bulgaria (created in 681AD by Khan Asparukh). Therefore, those ?barbaric? Bulgarians in a relatively short period of time (some less than 30 years) managed to not only establish an officially recognized state, but they succeeded in accomplishing this in spite of having the mightiest and most civilized empire as an arch-rival. That in itself is certainly worth considering, to say the least. To support this, it is important to mention that in 1972 a medieval seal was found which most probably depicts Khan Tervel and reads (in Greek) ?By Mary, protect Caesar Tervel? (this is my translation, based in turn on a Bulgarian translation of the actual seal). There even exist theories to suggest that Tervel was a Christian, and the inscription on the seal certainly lends them some credibility. In this text, a similar view is likewise purported: ?Tervel was rewarded with the almost imperial title of Caesar and, sitting enthroned beside the emperor, he received the obeisance of the citizenry. He displayed his new trappings on a seal which was perhaps struck for him while he was still in Constantinople.? pg 231The seal I am referring to above, that was discovered in 1972 seems a fair match for the account given in the above referenced text. All this undoubtedly serves to attest the view that Tervel?s achievements were considerable even before we arrive at the decisive Bulgarian contribution at the siege of Constantinople some 12 years later.  Again, I would like to stress the fact that at the time, the Bulgarian state was still in its infancy, yet it was already acquiring new lands speedily, both with the help of skilful diplomacy and military superiority; and Tervel?s recognition as ?Caesar? is unquestionably proof of the glory and I daresay, precocity of the Bulgarians when it came to upholding their will against the ?civilized? Byzantines at the same that they were open and receptive enough to gradually absorb the latter?s admittedly far superior culture. This is something which will follow for centuries to come. NOW I would consider it appropriate to start talking about the actual siege.  Perhaps the most notable contemporary source which directly deals with the Bulgarian factor in the siege, is that of Theophanes Confessor who states: ?The Bulgarian people raised war against them (the Arabs) and as those who know say, massacred up to 22,000 of the Arabs.?    (link)This is a Byzantine chronicler writing after the event and he openly acknowledges the significant contribution of the Bulgarians in the siege. Moreover, he uses the term ?war? to describe the struggle between them and the Arabs, which is arguably further suggestive of the enormous scale of the battle and the true magnitude of the Bulgarian involvement in it. The fact that Theophanes was a Byzantine scholar and yet spoke of the Bulgarians with noted respect and is not shy of placing an emphasis on Tervel?s substantial contribution to the defeat of the Arabs, only further goes to show the true significance of the role that the Bulgarians played in the siege.  Now, the supposed 250,000- strong Arab army is a dubious claim I admit, and it does seem a bit far-fetched and exaggerated. Remember that the siege lasted for about two years or more even however, and that the number of Arabs involved in it could have amounted to 200, 000 in the duration of the ENTIRE siege. The final battle which precluded the ultimate defeat of the Arabs and in which the Bulgarians took part, perhaps involved some 30,000 Arabs which certainly is a far more realistic number. Further evidence which similarly endorses the view that the Bulgarians bore a noteworthy influence upon the siege comes from am 18th century Franciscan monk possibly of German origin, Blasius Kleiner, who is credited as being the first person to write a history of Bulgaria following its fall to the Ottoman Empire four centuries earlier. His work is also noted for being historically objective and unbiased. Here is what he says:??in the second year of the reign of Byzantine Emperor Leo the Isaurian, the Saracins came to Constantinople with a countless army and besieged the city in the course of three years?they attacked the Bulgarians as well, but were defeated by them, and 22,000 of their number were massacred; the rest fled and returned to their ships.?As you can see, the ?22,000? Arabs massacred by the Bulgarians as stated in the source above, is in accord with Theophanes? account of the battle which I have likewise referenced above. Additionally, Michael the Syrian in his Chronicle notes:?The Arabs were attacked by land both by the people from the city [Constantinople] and by the Bulgars, and in the sea - by the Roman ships, and on the other side of the sea [on the coast of Asia Minor] by the Roman vanguard. They couldn't get out of the camp to a distance greater than two miles, while they were forced to search for wheat. The Bulgars attacked the Arabs and slew them; those latter [the Arabs] feared the Bulgars more than they feared the besieged Romans. The winter came, but the Arabs were afraid of retreating: first - because of their king, second - because of the sea and third - because of the Bulgars.?As such, all the sources agree that the Bulgarians played a decisive role in the siege and the battles which it comprised. Of course, the sheer length of the siege and the attrition within the Arab forces which sprung from it, as well as the onset of winter ? these were all likewise critical factors which led to the defeat of the Arabs. Nevertheless, Bulgarian aid was perhaps that one factor which contributed the most for the ultimate success of the Byzantines. Doesn?t the fact that Emperor Leo III had to ask the Bulgarians for help in the first place speak for itself? This precise fact indicates that the Byzantine forces most probably wouldn?t have held up even with Constantinople?s formidable walls against the relentless onslaught of the Arabs. Also, bear in mind that the Bulgarians at the time were still pagans as far as I am concerned, though theories do exist that Tervel converted them to Christianity during his reign, but the widely held view is still that it wasn?t until Boris I?s time that they were Christianized. For me it seems only logical that later documents (particularly with inherent Christian flavour) would have deliberately aimed at downplaying the role that the Bulgarians played in the siege. Who would have wanted to openly admit that the then capital of Christianity was saved by people who were still pagans? I?ll give you an example. One of the leading current Bulgarian historians, Professor Bozhidar Dimitrov says in an interview on this web page (translated from Bulgarian by me):?The crushing defeat of the Arabian invasion, which cut off Spain from Europe for eight centuries, by Khan Tervel in 716-718 is a Bulgarian victory, recognised by dozens of Medieval European authors. They were so impressed by this Bulgarian contribution for the preservation of Christian and European civilization, that they claimed other great deeds in his name for which he was not actually responsible. They write of how for example, Tervel decisively defeated all peoples heading towards Europe from the north and even the Christianization of Bulgaria. Tervel is a hero of dozens of Western European plays, novels, poetry anthologies, in all of which he is portrayed as crushing the enemies of Europe. The last book (written in 1648) ? 600 pages long ? is by the noted Italian humanist Francesco Bracciolini. In comparison ? a few days ago the much talked about book Charlemagne by one of the most renowned French scholars was published in our country. In reference to the fearful Arab danger at the beginning of the 8th century, he says that the Arabs besieged Constantinople, but ultimately they themselves felt besieged and thus perished. However, there is no mention of who actually besieged them or why they perished as a result. Moreover, ?Bulgaria? is referred to only once and in the following context: when Charlemagne crushed the Avars, the remainder of them fled to the ?future Bulgaria?. That was actually the Bulgaria ruled by Khan Krum, which was already in existence for 200 years. Even the diligent translator (the book was published with the support of the French Ministry of Culture) felt uncomfortable and in a footnote explained that for modern French historiography, Bulgaria sprung into existence merely after the Christianization. Many Europeans really wish for us never to have existed at all and take pleasure in crossing out entire centuries of our history.?The text quoted above is important for two main reasons:One is that it shows how Western historiography has consciously denigrated the contributions made by medieval Bulgaria, ignoring her existence as a powerful state completely sometimes even. The other reason is a more subtle one. In his reference to the eponymous book about Charlemagne, Dimitrov points that the Arabs ?themselves felt besieged? in the end.    Now, if we compare this with the information provided by the wikipedia article on the siege in question, we can discern certain parallels:?The Arabs were surprised by the new and unexpected enemy and his attack on their own camp, followed by a horrible massacre. Encouraged by this, the Byzantines opened the gates and attempted to break the siege, but were stopped at the Arab trenches and had to retreat back behind the city walls because of the following Arab counter-attack. This scene was repeated several times during the siege with the same ill success for both sides. The incessant Bulgar attacks in the rear of the Arabs forced them to build trenches also against the Bulgars. This way, however, the Arabs found themselves in a thin line between two fortifications, which were attacked both by Bulgars and Byzantines. After an unusually harsh winter, weary from the long attrition of siege warfare, thinned out by disease and hunger, and demoralized by the lack of success in assaulting the city, the Arabs attempted to retreat to their ships in July, but were devastated by a Bulgar attack against their land forces. Contemporary chroniclers report at least 12,000-15,000 Arabs died in the first Bulgar attack.?Both sources agree that the Arabs indeed were besieged by the Bulgarians from the rear, whilst they had to fight off Byzantine attacks as well from the front. Therefore, the evident pressure exerted by the Bulgarian forces from behind (no double meaning intended!) no doubt proved vital in trapping the Arabs and thus ?besieging? them. Probably that was the core reason for the massacre that ensued in the end, leaving the invaders with hardly any chance, making a retreat itself difficult. With all the evidence presented here, I think it?s only fair and reasonable to conclude that without the Bulgarian aid, the Byzantines wouldn?t have withstood the overwhelming army of the Arabs. It was the decisive defeat that the Bulgarians inflicted on the latter that put and an end to the influx of Arab forces laying a siege on Constantinople. The successes of the Bulgarian attacks also ultimately prompted a spiritual resurgence within the Byzantines as indicated by the text quoted above, which likewise arguably contributed to the rebuttal of the Arab advances. As I said before, think of the desperation which Leo III must have felt to have to seek Bulgarian support, seeing that the prospect of his capital falling was looming over it. Now that must have been a painful gasp for help! For a proud empire to plead for help from the ?barbarians? must have really meant that the situation was desperate. Also, had the Arabs seized Constantinople, the map of Europe would have undoubtedly been altered thereafter. Just think: if they had overran the Byzantines, it wouldn?t have been that hard for them to ultimately grip the whole of the Balkans with their claws, for Bulgaria herself was still an infant state which though of considerable military potential, would have been threatened greatly and possibly overwhelmed by the invading Arab forces which (confident by their conquest of Constantinople ? the greatest, most lavish city in the contemporary world)  would have stopped at nothing to advance further north, threatening the whole of Eastern Europe. I do not doubt that it was a likely scenario and therefore the siege itself deserves its place among the most significant macrohistorical instances in the history of Europe. Along with this, Khan Tervel?s Bulgarian forces fully deserve the credit they were given at the time, and which history (due to the intellectual hegemony of the West) has taxed of its significance. Now, I am sure you all are more erudite than myself on the subject of world history overall as you seem to be. I am only in my late teens and I can sense that you are considerably older than me (I might err there of course, who knows!), as I judge from your academic tone, objectivism and patience and evident respect for ivkho?s claims which I consider especially noble on your part. I myself have on occasions come to argue in favour of my country?s past glory, only to be met with derision by certain individuals who laugh off my claims, dismissing them as steeped in pathetic nationalistic fervor without much historical credibility. Yet, you seem far more intelligent and open-minded ? something which I admire.