Having considered the accounts of different sources, we may conclude on the main peculiarities of Byzantine military organization during these chronological frameworks. Under the reign of Heraclius (610–641) Byzantium received only two new and self-sufficient armies, that are Opsikion established between 615 and 626 and located in Constantinople, and Anatolikoi created at the end of Heraclius' reign, around 639, and initially stood in Cilicia, at the south-east of Asia Minor.

We suppose that up to 634, when the first Arabic invasion in Byzantium came (we mean the battles in Palestine), the old expeditionary (field) army of the East lost its significance of the most strike and effective military force at the Byzantine Near East. The reasons of these changes were the internal political disorders, which beat the Empire at the beginning of Heraclius' reign, in 610. In this year Comentiolus, a master of soldiers of the East (magister militum per Orientem), i. e. a supreme commander of expeditionary troops at the Byzantine Near East, became a main counterpart of Heraclius. Comentiolus was a brother of the Emperor Phocas, who had been deposed by Heraclius, Comentiolus raised an unrest and moved with his troops to Constantinople. But at the way to the city he was killed as a result of a plot held by the troops of expeditionary army of Armenia, which supported Heraclius. This conflict came to Heraclius' decision to leave a majority of expeditionary army of the East within the internal lands of Asia Minor in order to strengthen a control over this army, and the rest part of this army was backed to the Byzantine-Persian frontier. As a result, a size of troops, which had to defend Syria, Mesopotamia and Palestine, was seriously diminished.

Quite contrary, a significance of expeditionary troops of Armenia raised up, since that crucial moment the retinues of the nakharars, who were the chiefs of Armenian noble families, have became the basic element of expeditionary troops of Armenia. So, during the reign of Heraclius the retinues of the nakharars received a status of regular and permanent military units, they became an internal part of expeditionary troops of Armenia.

With regard to the army of Opsikion we may note that initially this army consisted of Moorish tribal units, which came in Asia Minor together with Heraclius from the Northern Africa, from the units of scholarioi, federates, boukellarioi, excubitores, and also regular detachments of two old central expeditionary armies, which located in Constantinople.

An Arabic invasion, which had been started in 634, annihilated expeditionary army of the East defeated in the battle at the Yarmouk river within Palestine in 636. The matter is that the army of Opsikion didn't take part in this battle, all the struggles were held by the troops of expeditionary army of the East. Respectively, close to 639 Heraclius was obliged to make a rapid withdrawal of these troops from Syria and Mesopotamia first in Isauria and then in internal regions of Eastern Asia Minor. In this way the army of Anatolikoi was established, in fact, it represented a rest of the old expeditionary army of the East.

The same fate took the armies of another two regions captured by the Arabs, that are Egypt and the Northern Africa. A strength of military garrisons, which defended Egypt from Arabic invasions, numbered approximately 200 men per each. More powerful was an army of the Northern Africa, it numbered nearly 30 000 soldiers. But the absolute majority of the Northern Africa's military forces placed in western parts of the region, that is on the territory of the provinces of Byzacena, Numidia and Africa Proconsularis, while Tripolitania (eastern parts of the Northern Africa, at the border of Egypt) rested without any serious regular military deployment. That's why when Byzantine army was defeated by the Arabs in 647 in the battle at the city of Sbeitla in Africa Proconsularis, the most sharp losses fell on the troops of Byzacena, Numidia and Africa Proconsularis, their military deployment suffered most seriously. For a little time, up to 668, a central administration of Byzantium kept some control over the lands of Tripolitania thanks to an expeditionary corps of a prominent and powerful Armenian nakharar Nerseh Kamsarakan, who came in these lands approximately in 647. But later, in 668, Byzantium was obliged to withdraw the rests of its army from Africa Proconsularis and Tripolitania to Sicily.

During the second half of the VIIth century an internal (organizational) structure of the Byzantine regional armies passed a set of serious changes, that is between 653–654 and 667–668 a central administration established a new army called Armeniakoi, it was headed not by the old official, that is a master of soldiers of Armenia, but by a strategos, in this case we may say about a creation of a new military office, that is a strategos of the Armeniakoi. Until 730th the ground of Byzantium's administrative-territorial division still were the old civic provinces established as early as during the Late Antiquity times, these provinces strictly have been existed since the reign of Justinian I. Moreover, up to the end of the VIIIth century a basic principle of power's separation (a clear distinction of civic and military branches of power) continued to exist. It means that the strategoi of the single regional armies didn't take and manage civic power' functions, they exercised military duties only. All the civic duties, such as judgment, a collection of taxes, control over the trade and movements of goods were supervised by the so-called kommerkiarioi, these financial officials placed in the special warehouses called apothekai.

Respectively, during the second half of the VIIth-VIIIth centuries each of the regional army located and covered a group of neighboring provinces at one time, to be more precise, the garrisons (fortresses) of each the army were spread over some neighboring provinces. Near to these fortresses was a place of apothekai, from which the kommerkiarioi supplied the troops with food, equipment and money. Only since the end of the VIIIth century the functions of supply gradually have came to another administrative service, that is the so-called protonotarioi, who were personal staff officials of a certain strategos and represented his auxiliary personnel. Protonotarioi subordinated to a strategos exclusively, a replacement of the kommerkia-rioi with the protonotarioi reflected a more global and deep processes, that are an addiction of the regional armies to defined territorial districts and a gradual conversion of these districts into the new military-administrative territorial units called the themes.

Since 717–718 seals have mentioned the provinces (αἱ ἐπαρχίαι) of different regional armies, we mean the armies of Armeniakoi, Anatolikoi and Opsikion. At the same time, the seals dated by times between 732–733 and 745–746 call these armies by the word στρατηγία — this word meant an army, military corps in proper sense, but not the territory, where the troops located. As a result, to our mind, since the early of the VIIIth century each of the regional army have been already addicted to a certain group of neighboring provinces where this army had stood previously, i. e. in fact, but we believe that the provinces themselves were strictly the old civic territorial units created as early as during the times of Late Antiquity.

We need to point out that in 680–681 the Emperor Constantine IV moved in the south-west of Asia Minor a group of troops from Thrace and in that way he established an army called Thrakesioi, this army was one of the four major regional armies of Asia Minor, alongside with the armies of Opsikion, Anatolikoi and Armeniakoi. In 809 the territories, where these troops had located, were modified into the themes, that are the military-administrative districts subordinated to a power of the strategoi, who, in turn, became a governors of the themes. Following J. Haldon's point of view, we think that the Emperor Nikephoros I, who reigned in that times, was a creator and founder of the theme order within Asia Minor, it was Nikephoros I who canceled an old system of civic provinces' division and replaced it with the new and more extended theme districts. In other words, the old civic provinces, which existed to 809, simply were unified in more large groups, and then these enlarged groups were converted into the theme districts, so, the civic administrative structures of the abolished provinces were subordinated to the new governors, that are the strategoi.

Since 809 the strategoi have managed the financial duties (a collection and distribution of taxes), judgment and civic government. But, at the same time, they commanded over the troops of the theme, controlled the provision of troops, recruitment and distributed a military salary. Obviously, after 809 a service of kommer-kiarioi as part of a local provincial government stopped to exist.

Meanwhile, within the Danube regions (that is Thrace), and also within the coastal lands (Peloponnese, Greece, Sicily) the theme administrative structures had been established long before 809 — the theme of Thrace was founded by 680–681, Peloponnese in 783 and Sicily — at the beginning of the VIIIth century. But, at the same time, the process of development of the theme structures was approximately the same in different regions — it means that each of the theme was divided in tourmai headed by the tourmarchoi, tourma, in turn, consisted of droungoi, and finally, each droungos included bandoi. Each theme had two extended services, the first one was a service of protonotarioi, who were responsible for food, monetary and logistic provision of the troops, and the second one was that of chartularioi, who managed recruitment and composed the lists of recruits. During a course of a next development the old large themes progressively were split out and the internal tourmai, which were singled out from these old themes, became the new and selfsufficient themes.

The seals of the strategoi of different themes led us to a conclusion that the titles of the strategoi didn't reflect and didn't mean a process of rise or fall of a strategic importance of a certain army within a defence system of Empire. The strategoi of all the armies (and next themes) generally disposed a double title, i. e. they had two titles at once, that of spatharios/protospatharios and patrikios. This peculiarity lead to a proposal that the seals of the strategoi reflect no rise or fall of the strategoi' political importance, but reflect a military career of their holders exclusively. First, the strategos received a title of spatharios/protospatharios, and then he obtained a title of patrikios. But, after having been awarded by a title of patrikios, the strategos in any case saved a previous title, a new title didn't annulated an old, in that manner a double title-system came in existence.

And the final step of our study, that are the social points, with respect to these issues we proposed that during all the period covered by our book Byzantium constantly disposed a well-trained mandatory system of recruitment and hereditary military service. The army was mainly a peasant, it means that predominantly it was filled up by the youth from peasant families, the state entrusted the peasant families with a task of provision and preparation of their sons for military service. In other words, a soldier's relatives had to collect food and money for soldier, and also their duty was to buy equipment for him, but the state didn't compensated them their expenses.

It's important to say that Byzantium of the VIIth-IXth centuries didn't possess any system of state conditional military landowning, in other words, the soldiers didn't receive from the state any lands in return for a military service. All the soldiers' lands represented a private family ownership of the soldiers, i. e. the soldiers received these lands not from the state, but from their parents by the right of inheritance. Respectively, the soldiers were collected together and sent in a certain garrison (fortress) or to a military campaign immediately, but for a time of military campaign only, so, after struggles had been completed, the theme armies were dispersed out and single soldiers returned to their private homes in the rural communities. These farmers-soldiers cultivated their lands and lived at the expense of these means until the new campaign would be started. When a new campaign was beginning and the male military capable farmers were going to army, a duty of cultivation the lands temporarily was imposed to the relatives of each the soldier, such the lands, together with a soldier-owner and his relatives, were ascribed to the special financial lists, by this way the state rigorously controlled over a process of provision the army at the cost of a civic population.

Generally, each military expedition presupposed and demanded a participation of three field (mobile) armies numbered 10–12 thousand men per each, and a strength of the rest armies, which didn't take part in campaigns but stood inside their relevant themes during a campaign (in order to make a defence of internal lands more better and effective), numbered 5–6 thousand men per each. To 773 a general count of all the Byzantine armies took together was nearly 80 000 men, while later, to 838–842/43, this count raised up to 120 000. And then, to the end of the IXth century, a general effective of Byzantine military forces reduced to 70 000 men, within this effective 40 000 men approximately were a count of a single military field group, which immediately took part in any campaign.