In the 18th century, Danish philology was advanced by Rasmus Rask, who pioneered the disciplines of comparative and historical linguistics, and wrote the first English-language grammar of Danish. Literary Danish continued to develop with the works of Ludvig Holberg, whose plays and historical and scientific works laid the foundation for the Danish literary canon. With the Danish colonization of Greenland by Hans Egede, Danish became the administrative and religious language there, while Iceland and the Faroe Islands had the status of Danish colonies with Danish as an official language until the mid-20th century.