Wilhelm was born in February 1786 in Hanau, in Hesse-Kassel. In 1803, he started studying law at the University of Marburg, one year after his brother Jacob started there. The two brothers spent their entire lives close together. In their school days, they had one bed and one table in common; as students, they had two beds and two tables in the same room. They always lived under one roof and had their books and property in common. In Berlin In 1825, 39-year-old Wilhelm married pharmacist's daughter Henriette Dorothea Wild, also known as Dortchen. Wilhelm's marriage did not change the harmony of the brothers. Richard Cleasby visited the brothers and observed, "they both live in the same house, and in such harmony and community that one might almost imagine the children were common property." Wilhelm's character was a complete contrast to that of his brother. As a boy, he was strong and healthy, but while growing up he suffered a long and severe illness which left him weak the rest of his life. He had a less comprehensive and energetic mind than his brother, and he had less of the spirit of investigation, preferring to confine himself to some limited and definitely bounded field of work. He utilized everything that bore directly on his own studies and ignored the rest. These studies were almost always of a literary nature.