IJssel in the context of "Natural harbour"

The Lordship of Overijssel or Overissel (Latin: Transisalania) is a former division of the Netherlands named for its position along the river IJssel. It corresponds to the modern day province of Overijssel.

The lordship was formed in 1528 when Charles V of Habsburg conquered Oversticht (roughly the present-day Province of Overijssel and Province of Drenthe), during the Guelders Wars. Before 1528, this area was part of the Bishopric of Utrecht. In 1528, at the demand of Henry of the Palatinate, Prince-Bishop of Utrecht, Habsburg forces under Georg Schenck van Toutenburg liberated the Bishopric, which had been occupied by the Duchy of Guelders since 1521–1522. On October 20, 1528, Bishop Henry handed over power to Charles of Habsburg. The Bishopric of Utrecht came to an end and was divided into the Lordship of Utrecht and the Lordship of Overijssel, both ruled by a Habsburg Stadtholder. The name Overijssel however is of much earlier date; Oversticht was known since 1233 by its Latin name Transysla or Transisalania, literally: Over-IJssel, i.e. the other side of the river IJssel.

Overijssel (Dutch pronunciation: [ˌoːvərˈɛisəl] ; Dutch Low Saxon: Oaveriessel [ˌɒːvərˈiːsl̩]; German: Oberyssel; lit. 'Outer IJssel') is a province of the Netherlands located in the eastern part of the country. The province borders Drenthe to the north, Friesland to the north-west, Flevoland (and a small part of the IJsselmeer) to the west, Gelderland to the south and west, and Germany's states of Lower Saxony and North Rhine-Westphalia to the east. Overijssel had a population of about 1,184,000 as of January 2023.

The province's name comes from the perspective of the Episcopal principality of Utrecht, which held the territory until 1528. The capital city of Overijssel is Zwolle (pop. 132,441) and the largest city is Enschede (pop. 161,235). The land mostly consists of grasslands and some forests (including Sallandse Heuvelrug National Park).

The Hollandse or Hollandsche IJssel (pronounced [ˌɦɔlɑntsə ˈʔɛisəl]; "Holland IJssel", as opposed to the 'regular' or Gelderland IJssel) is a branch of the Rhine delta that flows westward from Nieuwegein on river Lek through IJsselstein, Gouda and Capelle aan den IJssel to Krimpen aan den IJssel, where it ends in the Nieuwe Maas. Another branch called Enge IJssel ("Narrow IJssel") flows southwest from Nieuwegein. The name IJssel is thought to derive from the Germanic i sala, meaning "dark water". Originally, the Hollandse IJssel forked off from river Lek at Nieuwegein, but the connection was cut off with the Hollandse IJssel nowadays only draining the surrounding pastures.

If the North Sea floods, the Hollandse IJssel allows water through the Rotterdam Waterway to flood low-lying land east of Rotterdam. The Delta Works included a steel barrier that can be lowered within minutes to block the waterway. The sea protection constructions were built at the mouth of the Hollandse IJssel in 1957.

A terp, also known as a wierde, woerd, warf, warft, werf, werve, wurt or værft, is an artificial dwelling mound found on the North European Plain that has been created to provide safe ground during storm surges, high tides and sea or river flooding. The various terms used reflect the regional dialects of the North European region.

Terps are found in the coastal regions of the Netherlands, particularly in the provinces of Zeeland, Friesland and Groningen, as well as in southern Denmark and northwestern Germany. Before the construction of dykes, these mounds provided protection against floodwaters that regularly disrupted daily life. They are especially common in East Frisia (Ostfriesland) and Nordfriesland in Germany. On the Halligen islands in Kries Norfriesland, people continue to live on terps without the protection of dykes. Terps are also present in the Rhine and Meuse river plains in central Netherlands. Further examples occur in North Holland, such as Avendorp near Schagen, and in the towns of Bredene and Leffinge near Oostende in Belgium. Additional terps are located at mouth of the IJssel River, including at Kampereiland in the province of Overijssel, as well as on the former island of Schokland in the Zuiderzee, now part of the reclaimed Noordoostpolder. An old terp, known as Het Torp is also located beneath the town of Den Helder in North Holland.

The Zuiderzee or Zuider Zee (Dutch: [ˌzœydərˈzeː] ; old spelling Zuyderzee or Zuyder Zee), historically called Lake Almere and Lake Flevo, was a shallow bay of the North Sea in the northwest of the Netherlands. It extended about 100 km (62 mi) inland and at most 50 km (31 mi) wide, with an overall depth of about 4 to 5 m (13 to 16 ft) and a coastline of about 300 km (190 mi). It covered 5,000 km (1,900 sq mi). Its name is Dutch for "southern sea", indicating that the name originates in Friesland, to the north of the Zuiderzee (cf. North Sea).

It is generally acknowledged that the Zuiderzee existed from roughly 1170, following the devastating All Saints' Flood, until 1932, when the Afsluitdijk was completed. The majority of the Zuiderzee was closed off from the North Sea, leaving the mouth of the inlet to become part of the Wadden Sea. The salt water inlet changed into a fresh water lake now called the IJsselmeer (IJssel Lake) after the river that drains into it, and by means of drainage and polders, an area of some 1,500 km (580 sq mi) was reclaimed as land. This land eventually became the province of Flevoland. Part of the IJsselmeer was also divided into the Markermeer.

Kampen (Dutch pronunciation: [ˈkɑmpə(n)] ) is a city and municipality in the province of Overijssel, Netherlands. A member of the former Hanseatic League, it is located at the lower reaches of the river IJssel.

The municipality of Kampen had a population of 54,474 in 2021 and covers an area of 161.79 square kilometres (62.47 square miles). Kampen is located in the North West of Overijssel and is the largest city in this region. The city of Kampen itself has around 37,000 inhabitants.

The Nederrijn (Dutch pronunciation: [ˈneːdəˌrɛin]; "Lower Rhine"; distinct from the Lower Rhine or Niederrhein further upstream) is the Dutch part of the Rhine from the confluence at the town of Angeren of the cut-off Rhine bend of Oude Rijn (Gelderland) and the Pannerdens Kanaal (which was dug to form the new connection between the Waal and Nederrijn branches). The city of Arnhem lies on the right (north) bank of the Nederrijn, just past the point where the IJssel branches off. The Nederrijn flows on to the city of Wijk bij Duurstede, from where it continues as the Lek. The once-important but now small Kromme Rijn branch (in Roman times part of the Limes Germanicus and border river of the Roman Empire) carries the name "Rhine" towards the city of Utrecht.

From the city of Utrecht, the Kromme Rijn forks into the Vecht to the north, and into the Oude Rijn (Utrecht and South Holland) to the west. The first part is channelised and known as the Leidse Rijn (Leiden Rhine). After the railway bridge near Harmelen (municipality Woerden) it is known as the Oude Rijn, flowing westward to the North Sea.