Duke Otto von Brunswick I of Luneburg
Otto was born in 1204 in Braunschweig, Brunswick, Germany.  He died at the age of 48 on July 9th, 1252.

 Mathilde von Brandenburg
Mathilde was born in 1209 in Brandenburg, Prussia.  She died at the age of 52 on June 10th, 1261.

 Duke Albrecht ("the Great") von Brunswick I
Albrecht, known as "the Great", was born in 1236 in Braunschweig, Brunswick, Germany.  He died at the age of 43 on August 15th, 1279.