Jacoba C. Calkoen (1866-1944) was an important automatic writing and painting medium from Nijmegen in the Netherlands where she lived most of her life.
Although Jacoba Calkoen is forgotten now, she published several books in her day, including Levensopgang (1933), and was well-known and well-loved among Spiritualists.
In 2010, the archives of Jacoba C. Calkoen were discovered by Het Johan Borgman Fonds and transferred to Het Letterkundig Museum (The Dutch Museum of Literary Arts) in The Hague.
In addition, the archives of the Dutch Spiritualist Society "Harmonia" (Archive (HUA)) include records relating to Jacoba C. Calkoen.
The preliminary biographical sketch for this entry relating to the history of Spiritualism in the Netherlands was kindly provided by Mrs. Loes Modderman in December 2013.