Ulrich von Coler was an Oberleutnant in the Imperial German Army during World War I and an Oberst in the Finnish White Guard and Wehrmacht Heer in World War II. During the Finnish Civil War, he was one of 38 German officers in Finland and commanded the 2nd Jaeger Brigade Itäarmeija in Hanko. In 1919, Coler wrote a book called "Suomalaisten jääkärien parissa: muistelmia yhteistyön ajoilta 1915–1918", a curriculum vitae of his time in Finland during the First World War.

The 27th Jäger Battalion, officially called the Royal Prussian 27th Jäger Battalion was a jäger battalion of the Imperial German Army during World War I. The unit mainly consisted of Finnish volunteers that were a part of the Jäger movement.