"Rus' is almost another world" wrote the Krakow bishop Maciej around 1150. What was the basis of this differentiation? How powerful was it and how did it play out in reality? In search of answers, this article also discusses the dimensions and ambivalences of border demarcations.
Halyč-Volyn’ in the context of eastern Europe
In the western part of 
Kievan Rus'
rus. Киевская Русь, ukr. Київська Русь, deu. Altrussland (veraltet), deu. Kyjiver Rus, deu. Kiewer Rus’, eng. Kyivan Rus, bel. Кіеўская Русь, deu. Kiewer Reich

Kievan Rus' came into being when in the 9th century Scandinavian long-distance merchants and warriors, the Varangians, established bases along the river systems of Eastern Europe and subsequently mixed with the elites of the resident East Slavic population. It was a union of (partial) principalities with Kiev at its head. In the 11th and 12th centuries, Kievan Rus encompassed an area between Galicia and Volhynia (Halyč and Volyn’) to the southwest, Polock to the west, Novgorod to the northwest, Vladimir-Suzdal' to the northeast, and Kiev to the south.

, the two territories of 
Principality of Galicia–Volhynia
deu. Fürstentum Galizien-Wolhynien, deu. Fürstentum Halitsch-Wolhynien, eng. Kingdom of Galicia–Volhynia, deu. Russisches Königreich, deu. Ruthenisches Königreich, eng. Kingdom of Ruthenia, lat. Regnum Galiciæ et Lodomeriæ, eng. Principality of Halych-Volhynia

The principality of Galicia-Volhynia was formed around 1200 as an independent part of Kyiv Rus'. It continued to exist beyond the Mongol expansion as an independent political dominion until the 14th century.

 represented important centers of power, where various representatives of the Ryurik dynasty vied for supremacy. At the end of the 12th century they were united under Prince Roman. After the Mongol expansion completely rearranged the political map of eastern Europe in the mid-13th century, this principality preserved a certain independence – not only from 
Golden Horde
rus. Золотая Орда, . Altan Ord, . Алтан Орд, deu. Goldene Horde, eng. Ulus of Jochi, eng. Kipchak Khanate, deu. Kyptschak-Khanat, rus. Solotaja Orda

The Golden Horde was a Mongolian empire that came into being in 1236 under Khan Jötschi. The khans of the Golden Horde acted relatively autonomously from the Mongol Empire, of which the Golden Horde was formally a part until 1368. The Golden Horde ruled in Eastern Europe over the Principals of the Rus, who were tributary but also accountable to the Golden Horde. The Golden Horde's domain stretched from present-day Pakistan and the foothills of the Himalayas to present-day Hungary and Bulgaria.

, but also from the surrounding powers, namely the 
Grand Duchy of Lithuania
rus. Velikoe knjažestvo Litovskoe, rus. Великое княжество Литовское, pol. Wielkie Księstwo Litewskie, bel. Vialikaie Kniastva Litoŭskaie, bel. Вялікае Княства Літоўскае, lit. Lietuvos Didžioji Kunigaikštystė, lat. Magnus Ducatus Lituania, deu. Grpßfürstentum Litauen, Ruthenien und Schemaitien, deu. Großfürstentum Litauen

The territory of the Grand Duchy of Lithuania was settled by Baltic Lithuanians as early as the 11th century. These different "tribes" formed the Grand Duchy in the 13th century. The expansion of the Grand Duchy was mostly positioned to the east, as the Teutonic Order blocked the access to the Baltic Sea from the 13th century. In 1320, Grand Duke Gediminas conquered Kiev. From 1386, the Grand Duchy was under the same ruler as the Polish Kingdom (personal union) in order to be able to assert itself against the strengthening Teutonic Order in the region. In 1569, Poland and the Grand Duchy of Lithuania also became unified states.

, the 
Kingdom of Hungary
hun. Magyar Királyság, deu. Königreich Ungarn

The Kingdom of Hungary (Magyar Királyság) existed in changing borders since the year 1000. Already in the early modern period it fell to the Habsburg Monarchy, in which it later became the most important of the so-called Lands of the Hungarian Crown (also Lands of the Holy Hungarian Crown of St. Stephen or, after 1867, also called the Hungarian half of the Empire). Unlike other Habsburg territories - such as the lands of the Bohemian Crown or the Archduchy of Austria itself - the Kingdom of Hungary never belonged to the Holy Roman Empire.

 and the Polish principalities, which were reunited into one kingdom only at the beginning of the 14th century, under Władysław I. Of great importance for this was a clever marriage policy, which connected the princely family of the Kievan Rus’ with all surrounding dynasties. However, this then had the consequence that these kingdoms also laid claim to rule over the principality when the dynasty there died out at the beginning of the 14th century.1
Several military actions finally took place in the 1340s. Over the course of several campaigns, Polish King Kazimierz III, with Hungarian support, managed to conquer the southwestern parts of the principality around the centers of 
lat. Sanochia, pol. Królewskie Wolne Miasto Sanok, deu. Saanig, lat. Sanocum, yid. Sonik, ukr. Сянік

In the Middle Ages, Sanok was considered the "gateway to Hungary", guarded by castles of different construction periods. Sanok belonged to the Kievan Rus until the 12th century, when it was conquered by the Hungarians. From the 14th century, the town adopted Magdeburg town rights, and from the middle of this century, it belonged to the Kingdom of Poland.

rus. Peremyšlʹ, rus. Перемышль, ukr. Peremyšl′, ukr. Перемишль, deu. Deutsch-Przemysl, deu. Premissel

Przemyśl is strategically located between the Western Carpathians in the south and the Roztocze in the north. At the same time, in the Middle Ages, the town was located on the Via Regia. It is likely that a settlement on the territory of today's Przemyśl existed already in ancient times. From 1379, Przemyśl possessed the Magdeburg town charter under the Polish crown. After the first partition of Poland (1772) the town fell under the rule of the Habsburg monarchy and subsequently became the seat of the district authority of Przemyśl.

deu. Lemberg, pol. Lwów, eng. Lviv, rus. Lwow, rus. Львов, yid. Lemberg, yid. לעמבערג, ukr. Львів, ukr. L'viv

Lviv (German: Lemberg, Ukrainian: Львів, Polish: Lwów) is a city in western Ukraine in the oblast of the same name. With nearly 730,000 inhabitants (2015), Lviv is one of the largest cities in Ukraine. The city was part of Poland and Austria-Hungary for a long time.

Due to the war in Ukraine, it is possible that this information is no longer up to date.

eng. Halych, pol. Halicz, yid. Heylitsch, deu. Halitsch, rus. Galič, rus. Галич, ukr. Галич

Halich has existed as a settlement on the banks of the Dniester likely since the 10th century. In the 12th century, the castle is mentioned for the first time. Halich was the center of the principality of Halich-Volhynia. In 1240, the city was burned down by the Golden Horde. From 1367, Halich possessed the Magdeburg town charter under the Polish crown. The administrative unit of the Halich Land was part of the Ruthenian Voivodeship from 1569 to 1772. The town of Halich became famous because it gave its name to an entire Eastern European region, as Galicia is called "Halytschyna" in Ukrainian. The town has a ruined castle that is still visible today, perched on a steep rock overlooking the town centre.

, while the northern and eastern parts were annexed to the Grand Duchy of Lithuania. Halyčer Rus' (named after the former princely seat), Red Ruthenia or Crown Ruthenia are some of the different names for this region. I prefer the latter, which describes precisely those areas of Rus' that became part of the Crown of Poland.2
Polish conquest and administrative infiltration
During his campaigns of conquest, Kazimierz III and his advisors skillfully used the rhetoric of the Crusades to obtain financial support from the papal curia. Emphasis was placed on the heroic struggle against pagans and schismatics, the success of which would open vast new territories to the Latin Christian mission. This rhetoric, however, cannot hide the fact that from the very beginning Kazimierz depended on the cooperation of Rus' nobles to maintain control over the country. For example, the influential boyar boyar Boyars can be defined as prominent individuals who had close ties to the ruling families or even land ownership in the East Slavic principalities of Rus' as well as in the Grand Duchy of Lithuania. The Western European term "nobleman" is therefore to be understood only conditionally as an equivalent. A scientific summary of the term can be found at H. Rüß, 'Bojaren, I. Altrußland', in: Lexikon des Mittelalters, 10 Bde. Stuttgart: Metzler, 1977–1999, here vol. 2, sp. 354. Dmytr Det'ko was appointed as the first royal deputy. The key to success was ultimately that several leading Rus' families sided with the Polish king and were generously rewarded with land ownership.
The last decades of the 14th century saw a number of turbulent constellations of rulers in the Kingdom of Poland. After the death of Kazimierz III of the Piast dynasty in 1370, the crown passed to the Hungarian king Louis of Anjou. His daughter Jadwiga succeeded him in Poland in 1384. The following year she married the Grand Duke of Lithuania, Jogaila, which ultimately resulted in a personal union of the two kingdoms. As king Władysław II. Jagiełło, he founded the dynasty of the Jagiellonians, which was to leave a lasting mark on the political map of eastern Europe for centuries to come. The southwestern territories of Rus' were then reconquered for the Polish crown by Jadwiga and Jagiełło from 1387 after a brief period of Hungarian rule. However, they only became a regular voivodeship between 1430 and 1434 and remained so until the partitions of Poland-Lithuania at the end of the 18th century. 3 
The areas, partly depopulated as a result of numerous Tartar invasions, offered newcomers from East and West excellent opportunities for social advancement. Families settled here mainly from Lesser Poland, but also from Silesia and Bohemia as well as from Podolia or Lithuania. At the same time, the respective rulers used the region to reward their entourages with land and wealth, and thus to secure their loyalty. Among other things, this took the form of various kinds of land allocation via fiefdoms and pledges, which were also widespread in other areas of Europe. The region thus opened up opportunities for development and influence for both sides, although this was not without conflict. For example, the nobles who lived here now strove for legal equality with their neighbors in other areas under crown rule. However, this was only possible by adapting to the conditions in Poland, for example, converting to the Latin Christian faith or adopting the Latin written language. Thus, the pressure to assimilate was not a result of a program decreed by the "authorities," but of a complex interaction of social and political factors that only gradually unfolded. Nevertheless, various regional characteristics, such as the presence of Ruthenian as a legal language, persisted well into the 16th century. Likewise, the practice of giving oral testimony in court –  as was common in the era of the principality – remained highly significant even in the context of a broadly text-based and regulated administration.
Legal and religious diversity
Even before the Polish conquest, there had been Jewish and Armenian communities living in the cities of western Rus'. Of outstanding importance was the city of L'viv, where both groups were able to assert themselves particularly well against the Latin city council due to their influential role in Oriental trade. Based on its location, orient trade was the city's dominant position. The city was constituted by Saxon-Magdeburg law, which, in various regional adaptations, was applied to urbanization in much of eastern Europe in the 14th and 15th centuries. Even Kyiv received this legal city status at the end of the 15th century – at that time as part of the Grand Duchy of Lithuania.
 However, we should not assume that the division of the population into Armenians, Jews and Latins was based on rigid ethnic categories to which people belonged by birth. Rather, such legal and religious categories sometimes offered individuals astonishing leeway. An Armenian merchant could certainly slip under the umbrella of Saxon-Magdeburg law if he considered this advantageous for his business. The same was true for Ruthenian peasants, who might have expected better working conditions from another landlord. The conflicts did not become more frequent until the end of the 15th century, when the Ottoman expansion on the Black Sea made once lucrative commercial operations more difficult and led to increased struggles around distribution. Religious difference then became above all a rhetorical weapon, as it had been in the context of the conquest, and could be used for promising effect.
The formation of a dual ecclesial landscape
Already around the middle of the 14th century, the conquest by Kazimierz III created a situation that the treaty referred to as the 'Peace of Augsburg' did not intensively discuss for the Holy Roman Empire of German Nations until 200 years later: How could several Christian denominations coexist in parallel under one rule? In the first decades, this coexistence was unsuccessful less because of the irreconcilability of the denominations than because of organizational difficulties. The Polish king's earliest initiatives to found Latin Christian bishoprics fizzled out. Thus, there can be no question of a missionary policy often imputed to Kazimierz III in the 19th century.
The Patriarch in Constantinople also agreed to the attempt to found an Orthodox church Orthodox church An Orthodox metropolis is a union of Orthodox bishoprics under a chief bishop (metropolitan). This ecclesiastical order is closely linked to the political order of the country or region. With the rise in importance of the Orthodox patriarchates, the metropolises lost religious and political influence.  only after Kazimierz III had died. The first papal archbishopric was founded in 1375 with its seat in the old noble city of Halyč, but it took decades for it to really function. The same was true for the widespread establishment of parish churches, which only gained momentum in the second half of the 15th century. The ecclesiastical infrastructure repeatedly became a pawn in larger political developments: In 1412, for example, Władysław II had the Orthodox congregation expelled from their cathedral in Przemyśl, however not to in order to proselytize them, but to prove to the attending envoys of the Teutonic Order and the Kingdom of Hungary what an outstanding Latin Christian ruler he was. On the other hand, the Orthodox-Christian church was crushed by the compounding demands of the Grand Principalities of Moscow and Lithuania, but also of Constantinople, Hungary and Moldavia, and was abandoned in 1391. The question of how to deal with the Orthodox Christian inhabitants of Poland-Lithuania caused a bitter, centuries-long feud. After the Moscow Church finally broke away from Constantinople towards the end of the 16th century, the Church Union of Brest in 1596 created a constellation all of its own: the Orthodox believers within Poland-Lithuania recognized the Pope as their head and, by implication, were allowed to remain faithful to their rites.4 The Greek Catholic Church, which predominates in western Ukraine, bears witness to this connection to this day.5
Crown Ruthenia as a subject of research (19th-21st C.)
In the 19th century, when the imperially motivated nationalism of Greater Russia began to claim the heritage of Kyiv Rus' exclusively for Moscow, the principality of Halyč-Volyn’ gained an important role as a counter-narrative, since the tradition of the Kyiv grand princes had been continued in this western subkingdom. Both the Mongol invasion and the advance of Moscow would have been resisted here. Only the increasing oppression within Poland-Lithuania would have brought the Rus' statehood (here already understood as Ukrainian) to a temporary standstill, before it gained a new contour under the hetmans of the Cossacks in the 16th and 17th centuries. This is how Mychailo Hruševs'kyj, the most influential Ukrainian historian and later president of the short-lived Ukrainian People's Republic, put it. His multi-volume History of Ukraine-Rus' became a standard reference work around 1900.6
In contrast, Polish historiography emphasized the backwardness of the region before the Polish conquest. In a narrative similar to that of the German settlement in the East, the role of the bringer of civilization was attributed to the Kingdom of Poland and Kazimierz III in particular. Under the rule of the Jagiellonians, the various peoples would then have coexisted peacefully for centuries before the imperial expansions of the Russian Empire, as well as the Habsburgs and Prussians, put an end to this harmony. The competition between different historical narratives intensified in the 19th and early 20th centuries, when the region was part of the Habsburg crown land of "Galicia and Lodomeria". This potential for conflict was unleashed during and after World War I and led to the region's history almost becoming a taboo subject during the Soviet era. It was not until after 1991 that historical scholarship in Poland, Russia, Ukraine, as well as Belarus, Lithuania and Hungary, began to devote more attention to the region again. Since then, there have been successful steps towards transnational, dialogical research of the region's eventful heritage. It is to be hoped that the networks and cooperations that have emerged as a result will be resilient enough to survive the Russian war of aggression and its as yet hardly foreseeable consequences. 
The transformation of the former Rus' principality of Halyč-Volyn' into a Polish voivodeship was not a linear process of "westernization" or "civilization". Rather, both the respective rulers and the local people reacted situationally to new challenges as they arose. These constant processes of negotiation were by no means entirely peaceful; records show that, from the middle of the 15th century, there was a growing pressure to assimilate the non-Latin population. However, this did not follow a uniform program. There were always constellations and gray areas that left room for maneuvering and allowed special regional characteristics to be preserved. Within this mixed situation, clear boundaries can in fact only be found in the rhetoric of the Crusade, in which the region's position on the edge of (Latin) Christendom was stylized. In all other discussions of possible border dimensions – be they religious, linguistic, legal or political – overlaps and ambivalences dominate. The historical heritage of the region therefore bears witness to these complex interconnections, the traces of which are still visible today. It is precisely this diversity, however, that makes a study of this space so worthwhile and fascinating.