He is married to Hildegard von CRAMM.
They got married on July 21, 1870 at Ölber, he was 22 years old.
http://trees.ancestry.com/pt/AMTCitationRedir.aspx?tid=114784053&pid=774
http://trees.ancestry.com/pt/AMTCitationRedir.aspx?tid=159732775&pid=1333/ Ancestry.com
Leo Karl Wilhelm Otto Freiherr von Knigge<br>Gender: Male<br>Birth: May 23 1848<br>Occupation: hzl. braunschw. B.O. Jägermeister<br>Marriage: Spouse: Hildegard Frfr. Knigge (born Freiin von Cramm) - July 21 1870<br>Death: July 12 1906 - Braunschweig, Niedersachsen, Deutschland<br>Father: Otto Franz Frhr. Leopold Georg Knigge<br>Mother: Therese Frfr. Knigge (born von Landesberg)<br>Wife: Hildegard Frfr. Knigge (born Freiin von Cramm)</a><br>Children: Ottonie Frfr. von Stoltzenberg (born Freiin Knigge), Ada von der Decken (born Knigge)