One of the most well-known explorers and missionaries of the nineteenth century, Livingstone was horrified by the continuation of the slave trade in Africa, which overshadowed his expedition along the Zambesi river and, influenced by the abolitionist Thomas Fowell Buxton, argued that the "civilizing influence" of missionary activity and commerce was the only way of ending the trade. His eye-witness reports describing wars and slave raids on villages influenced the revived abolitionist movement from the late 1860s onwards, and helped to justify Europe's colonization of Africa. Livingstone, who considered his expedition the first to witness the entire process of enslavement, estimated that for every victim of slavery that reached the coast, another four died in wars or en route, and describes finding skeletons along the length of the expedition's route. In his Narrative of an expedition to the Zambesi, he recommends armed intervention to stop the trade.