 Hannah's developmental progress ("Entwicklung") was carefully documented by her mother in a book, which she titled "Unser Kind" (Our Child) and measured her against the benchmark of what was then considered "normale Entwicklung" ("normal development").Arendt attended kindergarten from 1910 where her precocity impressed her teachers and enrolled in the Szittnich School, Königsberg (Hufen-Oberlyzeum), on Bahnstrasse in August 1913, but her studies there were interrupted by the outbreak of World War I, forcing the family to temporarily flee to Berlin on 23 August 1914, in the face of the advancing Russian army.There they stayed with her mother's younger sister, Margarethe Fürst (1884–1942), and her three children, while Hannah attended a girl's "Lyzeum" school in Berlin-Charlottenburg.