John I, Margrave of Brandenburg ( – 4 April 1266) was from 1220 until his death Margrave of Brandenburg, jointly with his brother Otto III "the Pious".
The reign of these two Ascanian Margraves was characterized by an expansion of the Margraviate, which annexed the remaining parts of Teltow and Barnim, the Uckermark, the Lordship of Stargard, the Lubusz Land and parts of the Neumark east of the Oder. They consolidated the position of Brandenburg within the Holy Roman Empire, which was reflected in the fact that in 1256, Otto III was a candidate to be elected King of the Germans. They founded several cities and developed the twin cities of Cölln and Berlin. They expanded the Ascanian castle in nearby Spandau and made it their preferred residence.
Before their death, they divided the Margraviate into a Johannine and Ottonian parts. The Ascanians were traditionally buried in the Lehnin Abbey in the Ottonian part of the country. In 1258, they founded a Cistercian monastery named Mariensee, where members of the Johannine line could be buried. In 1266, they changed their mind and founded a second monastery Chorin, 8 km southwest of Mariensee. John was initially buried at Mariensee; his body was moved to Chorin in 1273.
After the Ottonian line died out in 1317, John I's grandson Waldemar reunited the Margraviate.
Life
Regency and guardianship John was the elder son of Albert II of the Brandenburg line of the House of Ascania and Mechthild (Matilda), the daughter of Margrave Conrad II of Lusatia, a junior line of the House of Wettin. Since John and his two-year-younger brother Otto III were minors when their father died in 1220, Emperor Frederick II transferred the regency to Archbishop Albert I of Magdeburg. The guardianship was taken up by the children's first cousin once removed, Count Henry I of Anhalt, the older brother of Duke Albert I of Saxony, a cousin of Albert II. As the sons of Duke Bernhard III of Saxony, they were the closest relatives, and Henry had the older rights.
In 1221, their mother, Countess Matilda, purchased the regency from the Archbishop of Magdeburg for 1900 silver Marks and then ruled jointly with Henry I.Stefan Warnatsch: Geschichte des Klosters Lehnin ..., p. 62 The Archbishop of Magdeburg then travelled to Italy to visit Emperor Frederick II, and Duke Albert I of Saxony attempted to grab power in Brandenburg, causing a rift with his brother Henry I. The Saxon attack allowed Count Palatine Henry V to get involved. Emperor Frederick II prevented a feud, urging them to keep the peace.
After Matilda died in 1225, the brothers jointly ruled the Margraviate of Brandenburg. John I was twelve at the time, and Otto III was ten. They were knighted on 11 May 1231 in Brandenburg an der Havel, which is generally taken as the beginning of their reign.brandenburg1260.de Marca BrandenburgensisLyon 2013, pp. 203
Domestic policies
After the death of Count Henry of Brunswick-Lüneburg in 1227, the brothers supported his nephew, their brother-in-law Otto the Child, who was only able to prevail against Hohenstaufen's claims and its vassals by force of arms. In 1229, there was a feud with former regent Archbishop Albert, which ended peacefully. Like their former opponents and defenders, they appeared at the Diet of Mainz in 1235, where the Public Peace of Mainz was proclaimed.
After the dispute over the kingship between Conrad IV and Henry Raspe the brothers recognized William II of Holland as King in 1251. They first exercised Brandenburg's electoral privilege in 1257, when they voted for King Alfonso X of Castile. Although Alfonso was not elected, the fact that they could vote illustrates the growing importance of Brandenburg, founded only a century earlier, in 1157, by Albert the Bear. When John and Otto came to power, Brandenburg was considered an insignificant little principality on the eastern border. By the 1230s, the Margraves of Brandenburg had gained the heritable post of Imperial Chamberlain and the indisputable right to vote in the election of the King of the Germans.Lutz Partenheimer: Albrecht der Bär ..., p. 195
Developing the country
John I and his brother Otto III developed the territory of their margraviate and expanded market towns and castles, including Spandau, Cölln and Prenzlau, into towns and centers of commerce. They also expanded Frankfurt an der Oder, and John I awarded it city status in 1253.
The Teltow War and the Treaty of Landin Between 1230 and 1245, Brandenburg acquired the remaining part of Barnim and the southern Uckermark up to the Welse river. On 20 June 1236, the Margraviate acquired the Lordships of Stargard, Beseritz, and Wustrow by the Treaty of Kremmen from Duke Wartislaw III of Pomerania. Later that year, the brothers initiated the construction of Stargard Castle to secure the northernmost part of their territory.
From 1239 to 1245, the brothers fought the Teltow War against the Margraves of Meissen of the House of Wettin. At stake was a Slavic castle at Köpenick, a former headquarters of the Sprewanen tribe, located at the confluence of the Spree and Dahme rivers. At the time, it was just east of Berlin; today, it is part of the city. It dominated the Barnim and Teltow areas. In 1245, the brothers managed to take the castle at Köpenick and a fortress at Mittenwalde. From this base, they could expand further to the east. In 1249, they acquired the Lubusz Land and reached the river Oder.
In 1250, the brothers closed the Treaty of Landin with the Dukes of Pomerania. Under this treaty, they received the northern part of the Uckermark (), north of the Welse River and the districts of Randow and Löcknitz in exchange for the half of the Lordship of Wolgast that John I had received as dowry from King Waldemar II of Denmark when he married his first wife, Sophia. This treaty is considered the birth of the Uckermark as a part of Brandenburg.Uwe Michas: Die Eroberung und Besiedlung ..., p. 41
Policies to stabilize the Neumark During the first third of the 13th century, German settlers were recruited by Duke Leszek I the White to settle in Neumark. After he died in 1227, the Polish central government collapsed, allowing the Margraves of Brandenburg to expand eastwards. They acquired land east of the Oder and expanded their domain further east to the river Drawa and north to Persante. In 1257, John I founded the town of Landsberg (now called Gorzów Wielkopolski) as an alternative river crossing across the Warta, competing with the crossing in the Polish town of Santok, detracting from the considerable revenues Santok made from foreign trade (customs duties, fees from the market operation and storage fees), similar to the way Berlin had been founded to compete with Köpenick. In 1261, the Margraves purchased Myślibórz (German: Soldin) from the Knights Templar and began developing the town into their power center in the Neumark.
The Margraves used the tried and tested Ascanian policy of founding monasteries and settlements to stabilise their new possessions. As early as 1230, they supported the Polish Count Dionysius Bronisius when he founded the Cistercian Paradies Monastery near Międzyrzecz (Meseritz) as a filiation of the monastery at Lehnin. Their cooperation with the Polish count provided border security against Pomerania and prepared the area's economy for integration into the Neumark. Among the settlers in the Neumark was the von Sydow family, who were later ennobled. The small town of Cedynia (Zehden; today in the Polish Voivodeship of West Pomerania) was enfeoffed to the noble von Jagow family.
The historian Stefan Warnatsch has summarized this development and the attempts of the Ascanians to gain access to the Baltic Sea from the middle Oder and the Uckermark as follows: The great success of the territorial expansion in the 13th century was mainly due to the great-grandsons of Albert the Bear. The design of their reign reached much further spatially and conceptually than their predecessors.Stefan Warnatsch: Geschichte des Klosters Lehnin ..., p. 26 According to Lutz Partenheimer: [around 1250], the Ascanians had pushed back their competitors from Magdeburg, Wettin, Mecklenburg, Pomerania, Poland and the smaller competitors on all fronts. However, John I and Otto III could have produced a strategically important connection to the Baltic Sea.
Development in the Berlin area The development of the Berlin area is closely related to the other policies of the two Margraves. The two founding cities of Berlin (Cölln and Berlin) were founded relatively late. The settlements began around 1170 and achieved city status around 1240.Wolfgang Fritze: Gründungsstadt Berlin. Die Anfange von Berlin-Cölln als Forschungsproblem, Potsdam, 2000 Other settlements in the area, such as Spandau and Köpenick, date back to the Slavic period (from about 720). These naturally had a greater strategic and political importance than the young merchant towns Cölln and Berlin. For a long time, the border between the territories of the Slavic tribes Hevelli and Sprewanen crossed straight through the area of today's Berlin. Around 1130, Spandau was an eastern outpost of the Hevelli under Pribislav. When Pribilav died in 1150, Spandau fell to Brandenburg under the terms of an inheritance treaty between Pribislav and Albert the Bear. Brandenburg did not acquire Köpenick until 1245.
Residence at Spandau
In 1229, the Margraves of Brandenburg lost a battle against their former guardian, the archbishop of Magdeburg at the Plauer See, close to their residence in Brandenburg an der Havel. The escaped to the fortress at Spandau. In the following years, the brothers made Spandau their preferred residence, next to Tangermünde in the Altmark. Between 1232 and 1266, seventeen stays at Spandau have been documented, more than at any other town.Felix Escher: Der Wandel der Residenzfunktion. ..., p. 161
Albert the Bear probably expanded the fortress island at Spandau eastwards before or shortly after his victory against a certain Jaxa (this was probably Jaxa of Köpenick) in 1157. Towards the end of the 12th century, the Ascanians moved the fortress about a kilometer to the North, to the location of today's Spandau Citadel, probably because of a rising ground water table. The presence of an Ascanian fortress on this site in 1197 has been established.Winfried Schich: Die Entstehung der mittelalterlichen Stadt Spandau. ..., p. 63f John I and Otto III expanded the fortress and promoted the civitas in the adjacent settlement. They gave it city rights in 1232 or earlier. They founded the Benedictine nunnery of St. Mary in 1239. The Nonnendammallee, one of the oldest streets in Berlin and as Nonnendamm part of a trade route as early as the 13th century, is still a reminder of the former nunneryNonnendammallee, in: Straßennamenlexikon des Luisenstädtischen Bildungsvereins
Expansion of Cölln and Berlin
According to the current state of research, no evidence has been found that a Slavic settlement existed in the area around the twin towns of Berlin and Cölln.Winfried Schich: Das mittelalterliche Berlin, ... S. 151 The ford across the largely swampy Berlin Glacial Valley gained importance during the Slavic-German transition period, when John I and Otto III settled the sparsely populated plateaus of Teltow and Barnim with local Slavs and German immigrants.