On 22 January 1861, Burton and Isabel married in a quiet Catholic ceremony although he did not adopt the Catholic faith at this time. Shortly after this, the couple were forced to spend some time apart when he formally entered the Diplomatic Service as consul on the island of Fernando Po, now Bioko in Equatorial Guinea. This was not a prestigious appointment; because the climate was considered extremely unhealthy for Europeans, Isabel could not accompany him. Burton spent much of this time exploring the coast of West Africa, documenting his findings in "Abeokuta and The Cameroons Mountains: An Exploration" (1863), and "A Mission to Gelele, King of Dahome" (1864). He described some of his experiences, including a trip up the Congo River to the Yellala Falls and beyond, in his 1876 book "Two trips to gorilla land and the cataracts of the Congo".