Slavery was a widespread phenomenon in Europe during the Atlantic slave trade of the 1500s to the 1800s, particularly around port cities and in their hinterlands. The slaves held around the Mediterranean and more widely around Europe included both “Atlantic” slaves and slaves of other geographical origins, primarily the Ottoman Empire, Indian Ocean colonies, and sub-Saharan Africa. Others came from the Black Sea and Eastern Europe. Sub-Saharan Africans arrived in Europe via the Barbary Regency ports and Egypt. Slaves’ personal histories were often complex and surprising because of the intricacies of global slave mobility and continuous changes of ownership. There is a general theoretical distinction between captives from the Ottoman Empire and its satellite states, defined as temporary slaves, and slaves from the Atlantic or sub-Saharan Africa, even if they sometimes lived the same experience in Europe. Ransom demands and payments were a significant form of commerce in the Mediterranean basin until the middle of the 19th century and slavery persisted in Europe throughout the 1800s. The process of slaves’ assimilation into the European system ran parallel with learning a new language and becoming Christian. Starting work for a new owner, governmental or private, involved the imposition of a new social and cultural identity. Many enslaved often sought out pathways to emancipation. This article presents more detailed analyses on the Italian and German territories, Austria, France, Britain, and Portugal.