Groenlo is a city in the Achterhoek region. Until 1 January 2005, Groenlo was an independent municipality and until 19 May 2006 Groenlo was the official name of the new municipality of Oost Gelre. On January 1, 2007, Groenlo together with the neighborhood Zwolle had 10,062 inhabitants.
Groenlo originated in the beginning of the seventh century, around 610, when the Saxons settled in Achterhoek. Groenlo is founded on the high side of the river Groenloose Slinge. On this side of the river were several aces. The north side of the Groenslose Slinge was a lower area. For the rest, around Groenlo there were a number of marshes, most of which have been mined over the centuries. So around 809, the kerspel Groenlo, with the first simple parish church dedicated to the holy Calixtus, is created. From other churches in Groenlo belonging to the Bisdom Münster, other churches were later established in neighboring places such as Eibergen, Borculo and Lichtenvoorde. Statically, Groenlo belonged to the county of Lohn. When the glory Borculo set apart from Lohn, Groenlo went to Borculo's lords.
As an old city, Groenlo has various sights that refer to the history of the city, especially of the era of the eighties war. An example is the Old Calixtuskerk, the oldest still existing church of Groenlo, built in late Gothic style between 1275 and 1520 commissioned by the bishop of Münster. The church has met all the sieges of Groenlo. Another building was formerly the New Calixtus church, nowadays the Saint Calixtus Basilica. This is a Catholic church in Groenlo, built in the early 20th century. Furthermore, in Groenlo there are still the Mussenbergbolwerk, the town farm and Nahuis Steamwood sawmill.