| Conventional Long Name: | Teisterbant |
| Common Name: | Teisterbant |
| Subdivision: | County |
| Nation: | Middle Francia |
| Government Type: | County |
| Title Leader: | Count |
| Leader1: | Gerolf of Holland |
| Year Leader1: | 889-987 |
| Leader2: | Ansfried van Huy |
| Year Leader2: | ?-995 |
| Leader3: | Balderic of Utrecht |
| Year Leader3: | 1017-1018 |
| Leader4: | Adalbold II of Utrecht (last) |
| Year Leader4: | 1026-? |
| Today: | Gelderland, Netherlands |
| Year Start: | 843 |
| Year End: | 1026 |
| Event Start: | Treaty of Verdun |
| Event End: | Incorporation into the Episcopal principality of Utrecht |
| Era: | Middle Ages |
| S1: | Episcopal principality of Utrecht |
| Flag S1: | Flag of the prince-bishopric of Utrecht.svg |
| S2: | Guelders |
| Flag S2: | Blason ville fr Avanne-Aveney (Doubs).svg |
| Border S2: | no |
| S3: | Duchy of Cleves |
| Flag S3: | Arms of the House of Cleves.svg |
| Border S3: | no |
| S4: | Land van Altena |
| Flag S4: | Wapen van Altena.png |
| Border S4: | no |
| S5: | County of Buren |
| Flag S5: | Buren-county.PNG |
| Border S5: | no |
Teisterbant was a pagus (province) of Lotharingia/Middle Francia. It was located in the present-day Netherlands, bordered by the rivers Lek and Waal.[1] Modern-day West-Betuwe (the southern part of the province of Gelderland) shares most of the same land including towns such as Batenburg, Vianen, Tiel, Culemborg, Geldermalsen. The historic fiefdoms of Altena, Arkel, Buren, Heusden and Vianen were also part of it.
The name Teisterbant probably comes from Celtic, meaning 'right' (compare teister with the Latin dexter, which means 'right'). This makes it the counterpart of Swifterbant, 'located on the left'. In the 8th century, it was a well-known area.[2] From 843 (after the Treaty of Verdun) to the death of Lothair II in 869, Teisterbant was ruled by Middle Francia. In 870, following the Treaty of Meerssen, Teisterbant came to Lothair's uncle Louis the German and became part of East Francia.
After expelling the Normans by the East Frankish king Arnulf of Carinthia on August 4, 889, Count Gerolf of Holland was given full ownership of a number of lands and properties. He was given several farms and houses in Tiel, Aalborg, and Asch, among others. He was also granted additional property in his own county, consisting of a forest and agricultural lands, situated somewhere between the mouth of the Old Rhine and (presumably) Bennebroek. Gerolf had two sons, Waldger and Dirk. Dirk's descendants became the counts of Holland. Waldger was count of Teisterbant from 898 to 928.[3] He was succeeded by his son Radboud, possibly also called "Poppo".
At the end of the 10th century the area came into the possession of Count Ansfried of Huy. Around 985 he gave up his belongings to live in a monastery. In 994 he was elected bishop of Utrecht. On April 11, 999, Holy Roman Emperor Otto III was given the royal property that "Poppo, son of Wedigeri" in Teisterbant had borrowed from the church of Utrecht.[4] The title count of Teisterbant went to Ansfried's cousin Unruoch (Hunerik), possibly father of Herman van Malsen, ancestor of the lords of Cuijk.
In 1026 Adalbold II acquired the title of count of Teisterbant. The diocese had already acquired several lands, which formed the basis for the Episcopal principality of Utrecht. Parts were issued in loan to the counties of Cleves and Guelders, as well as several honors. Eventually, Teisterbant lost its sovereignty to the diocese, and Teisterbant disappeared from the map.
Later, the area became a zone of contention between the dukes of Brabant and Gelre, because of its strategic location.