Emigration has been a central feature of Highland history over the last three centuries and, for much of that period, the scale of outward movement was significantly greater than that from other areas of Scotland. Clearances, commercialisation, demographic pressures, famine, economic collapse and landlordism all had an impact on the emigration process, though there is much debate among scholars about the precise and relative significance of these various influences. After the end of the Napoleonic Wars, the economic and demographic pressures on the population perceptibly increased. The landlord role was often crucial in translating the social crisis into high levels of emigration and also in fashioning the composition and structure of the emigrant parties and this was not only because proprietors covered transport costs. Landlord pursuit of profit and the ensuing commercialisation of estates were the main reasons for the development of mass emigration in the first place.