Rubuta ci gaba don wannan sakin layi - Shi ɗan Hans Christoph von Gagern ne, ministan jihar a Nassau; ya halarci makarantun motsa jiki a Kreuznach, Mannheim, da Weilburg, kuma ya yi karatun doka daga 1826 a Heidelberg, Utrecht, da Göttingen. Bayan ya zauna a Paris ya sami matsayi a cikin majalisar William I, Sarkin Netherlands a 1829. A farkon juyin juya halin Belgium
(1830) ya shiga rundunar sojojin Holland a matsayin mai sa kai kuma ya shiga cikin yaki da Belgium. A cikin 1833 ya yi ritaya daga hidimar Netherlands, ya auri Franzina Lambert, na Hague, kuma ya ɗauki karatun tarihi don ya dace da matsayin Privatdozent a Jami'ar Bonn. Ya kasance a Bonn a cikin shekarun 1837-40. A shekara ta 1837, ko da yake har yanzu shi ɗan Furotesta ne, ya goyi bayan Archbishop na Cologne, Droste-Vischering, wanda aka tsare, kuma ta haka ne ya rasa tagomashin Gwamnatin Prussia. A cikin 1840 an nada shi magajin minista tare da taken Legationsrat daga Duke na Nassau.