According to Jack Zipes, at this point "the Grimms were unable to devote all their energies to their research and did not have a clear idea about the significance of collecting folk tales in this initial phase." During their employment as librarians—which paid little but afforded them ample time for research—the brothers experienced a productive period of scholarship, publishing a number of books between 18.
They went on to publish works about Danish and Irish folk tales and Norse mythology, while continuing to edit the German folk tale collection.
Through Savigny and his circle of friends—German romantics such as Clemens Brentano and Ludwig Achim von Arnim—the Grimms were introduced to the ideas of Johann Gottfried Herder, who thought that German literature should revert to simpler forms, which he defined as The brothers dedicated themselves with great enthusiasm to their studies, about which Wilhelm wrote in his autobiography, "the ardor with which we studied Old German helped us overcome the spiritual depression of those days." Jacob was still financially responsible for his mother, brother, and younger siblings in 1805, so he accepted a post in Paris as research assistant to von Savigny.In 1796, Philipp Grimm died of pneumonia, plunging his family into poverty, and they were forced to relinquish their servants and large house.Dorothea depended on financial support from her father and sister, first lady-in-waiting at the court of William I, Elector of Hesse.In Kassel, they became acutely aware of their inferior social status relative to "high-born" students who received more attention.Still, each brother graduated at the head of his class: Jacob in 1803 and Wilhelm in 1804., the brothers attended the University of Marburg.