Mazovia in the context of "Collector of Russian lands"

Płock (pronounced [pwɔt͡sk] ), officially the Ducal Capital City of Płock, is a city in central Poland, on the Vistula river, in the Masovian Voivodeship. According to the data provided by GUS on 31 December 2021, there were 116,962 inhabitants in the city.

Płock is a seat of the county (powiat) in the west of the Masovian Voivodeship. From 1079 to 1138 it was the capital of Poland. The Cathedral Hill (Wzgórze Tumskie), along with Płock Castle and the Catholic Cathedral containing the sarcophagi of some Polish monarchs, is listed as a Historic Monument of Poland. It was the main city and administrative center of Mazovia in the Middle Ages before the rise of Warsaw, and later it remained a royal city of Poland. It is the cultural, academic, scientific, administrative and transportation center of the west and north Masovian region. Płock is the seat of the Roman Catholic Diocese of Płock, one of the oldest dioceses in the country, founded in the 11th century, and it is also the global headquarters for the Mariavite Church. Poland's oldest school and largest oil refinery are located in Płock.

Ostrołęka (Polish: [ɔstrɔˈwɛŋka] ; Yiddish: אסטראלענקע, romanized: Ostrolenka) is a small city in northeastern Poland on the Narew river, about 120 km (75 mi) northeast of Warsaw, with a population of 51,012 (2021) and an area of 33.46 square kilometres (12.92 sq mi). It is the capital of both Ostrołęka County and Ostrołęka City County in the Masovian Voivodeship.

Ostrołęka was founded as a medieval stronghold that grew into an important royal city in northern Mazovia, which prospered from crafts and trade. The city was the site of several battles and skirmishes throught history. Until the late 1980s, Ostrołęka was a local railroad junction, with four lines stemming from Ostrołęka railway station: eastwards to Łapy and Białystok, southwestwards to Tłuszcz and Warsaw, northwards to Wielbark and Olsztyn, and southwards to Małkinia. Ostrołęka is a local centre of culture and light industry. The Ostrołęka Power Station is located in Ostrołęka.

Warmian–Masurian Voivodeship is a voivodeship (province) in northeastern Poland. Its capital and largest city is Olsztyn. The voivodeship has an area of 24,192 km (9,341 sq mi) and in 2019 had a population of 1,425,967.

Warmian–Masurian Voivodeship was created on 1 January 1999 from the entire Olsztyn Voivodeship, the western half of Suwałki Voivodeship, and part of Elbląg Voivodeship, pursuant to the Polish local government reforms adopted in 1998. The province's name derives from two historic regions, Warmia and Masuria, although also parts of other regions are located within the province, i.e. of Chełmno Land, Powiśle, Mazovia, Bartia and Natangia.

The Lugii (or Lugi, Lygii, Ligii, Lugiones, Lygians, Ligians, Lugians, or Lougoi) were a group of tribes mentioned by Roman authors living in ca. 100 BC–300 AD in Central Europe, north of the Sudetes mountains in the basin of upper Oder and Vistula rivers, covering most of modern southern and middle Poland (regions of Silesia, Greater Poland, Mazovia and Lesser Poland).

Most archaeologists identify the Lugians with the Przeworsk culture, which is also associated with the Vandals, and it has been suggested that the Lugians and Vandals may have been closely related or even the same. While this culture was strongly Celtic-influenced in early Roman times, the Lugii are also sometimes regarded as Germanic, like the Vandals.

The Duchy of Masovia was a district principality and a fiefdom of the Kingdom of Poland, existing during the Middle Ages. The state was centered in Mazovia in the northeastern Kingdom of Poland, and during its existence, its capital was located in the Płock, Czersk and Warsaw. It was formed in 1138 from the territories of the Kingdom of Poland, following its fragmentation, that was started by the testament of Bolesław III Wrymouth. The country existed in the years: 1138–1275, 1294–1310, 1370–1381, and 1495–1526, between that time, going through fragmentations of its territory into smaller duchies and its unification. The states formed during its fragmentation were duchies of Kuyavia, Dobrzyń, Czersk, Płock, Warsaw, Rawa and Belz. In 1526, the country was incorporated into the Kingdom of Poland.

Czersk (Polish pronunciation: [t͡ʂɛrsk] ) is a settlement in the administrative district of Gmina Góra Kalwaria, within Piaseczno County, Masovian Voivodeship, in east-central Poland. The village also lies on the Czersk Lake (size: 9 hectares), which is an oxbow lake of the Vistula.

Czersk was an important settlement in the past and is one of the oldest Mazovian cities, famous for ruins of a medieval castle constructed in the late 14th century. It was a royal town of the Crown of the Kingdom of Poland in the past. In 1247–1526, it was the capital of the Duchy of Czersk, one of medieval Polish duchies. After incorporation of Mazovia into Poland (1526), the duchy was turned into the Czersk Land (see ziemia), part of Masovian Voivodeship (1526–1795). The Land of Czersk was divided into four counties - those of Czersk, Grójec, Garwolin (since 1539), and Warka. Czersk itself was the seat of castellans, who also were senators of the Polish–Lithuanian Commonwealth.

Bolesław the Pious (1224/27 – 14 April 1279) was a Duke of Greater Poland during 1239–1247 (according to some historians during 1239–1241, sole Duke of Ujście), Duke of Kalisz during 1247–1249, Duke of Gniezno during 1249–1250, Duke of Gniezno-Kalisz during 1253–1257, Duke of the whole of Greater Poland and Poznań during 1257–1273, in 1261 ruler over Ląd, regent of the Duchies of Mazovia, Płock and Czersk during 1262–1264, ruler over Bydgoszcz during 1268–1273, Duke of Inowrocław during 1271–1273, and Duke of Gniezno-Kalisz from 1273 until his death.

He was the second son of Władysław Odonic, Duke of Greater Poland by his wife Jadwiga, who was probably the daughter of Mestwin I, Duke of Pomerania, or a member of the Přemyslid dynasty. His name was very popular in the Piast dynasty, so it is unknown exactly after whom he was named. Very soon Bolesław received the nickname of "the Pious" (Latin: Pius, Polish: Pobożny), given to him during his lifetime by the Chronicle of the Chapter of Poznań. In 1264, Bolesław granted the first written privilege to the Jews of Greater Poland.

Masuria (Polish: Mazury [maˈzurɨ] ; Masurian: Mazurÿ; German: Masuren [maˈzuːʁən] ) is an ethnographic and geographic region in northern and northeastern Poland, known for its 2,000 lakes. Masuria occupies much of the Masurian Lake District. Administratively, it is part of the Warmian–Masurian Voivodeship (administrative area/province). Its biggest city, often regarded as its capital, is Ełk. The region covers a territory of some 10,000 km which approximately 500,000 people inhabit.

Masuria is bordered by Warmia, Powiśle and Chełmno Land in the west, Mazovia in the south, Podlachia and Suwałki Region in the east, and Lithuania Minor in the north.