Migration from Britain to another country could occur for many different reasons: employment prospects, family ties, marriage and the impact of specific crises could all stimulate such moves. The factors considered in Chapters 5 to 8 are thus all relevant to overseas migration which, in effect, was no more than an extension of long distance internal migration. However, the nature, characteristics and impacts of overseas migration are sufficiently distinctive to merit separate consideration. The term emigration is not easy to define precisely. It is usually taken to imply a move to another country in which there was an intent to settle permanently. However, the definition of permanent settlement is always nebulous in migration studies and intentions are very hard to discover for past events. Furthermore, the reasons given by family historians for movement overseas-which were gleaned from a range of public and personal documentary records-are also confusing. In some cases ‘emigration’ was stated as a reason for moving, in other cases more specific reasons such as work or to join other family members were stated as the reasons for migrating overseas. Whilst some such moves were permanent, and in any definition would be classed as emigration, in other cases they included temporary (though sometimes prolonged) periods of overseas employment during which there was always an intention to return to Britain. Moreover, some ‘emigrants’ also returned to Britain and others who initially moved temporarily eventually settled overseas. To avoid making arbitrary distinctions, in this chapter all migration from Britain to other countries is included, with the exception of moves undertaken when employed in the armed services. Clearly movement from Britain to France with a regiment during the First World War was not emigration! Return migrants are all those (excepting people moving with the armed services) who moved from Britain overseas and, at some time, returned to live in Britain for a period of time. The life-time migration histories collected by family historians allow overseas migration to be placed within a broader context, relating it to both the pattern of internal migration which occurred before an overseas move and to the incidence of return migration.