Complex sentence: Nearby villagers in the Borrum valley housed Detzner and his remaining men, which relieved the missionaries of direct responsibility for him, and there Detzner established his base camp from which he could mount his expeditions.
Split into simpler sentences: Nearby villagers in the Borrum valley housed Detzner and his remaining men, which relieved the missionaries of direct responsibility for him. There Detzner established a base camp from which he could mount his expeditions.