Particularly after the end of the boom created by the Revolutionary and Napoleonic Wars (1790–1815), these landlords needed cash to maintain their position in London society. They turned to money rents and downplayed the traditional patriarchal relationship that had historically sustained the clans. One result of these changes were the Highland Clearances, in which many tenants in the Highlands were evicted as lands were enclosed, principally so that they could be used for sheep farming. The clearances followed patterns of agricultural change throughout the UK, though were notorious as a result of the introduction of Lowland farmhands or practice into Highland agricultural land or practice, plus the lack of legal protection for year-by-year tenants under Scots law, and the abruptness of the change from the traditional clan system. The result was a continuous exodus from the land—to the cities, or further afield to England, Canada, America or Australia. The Lowland and Highland Clearances meant that many small settlements were dismantled, their occupants forced either to the new purpose-built villages built by the landowners such as John Cockburn's Ormiston or Archibald Grant's Monymusk on the outskirts of the new ranch-style farms, or to the new industrial centres of Glasgow, Edinburgh, or northern England. Tens of thousands of others emigrated to Canada or the United States, finding opportunities there to own and farm their own land. In the Highlands many that remained were now crofters, living on very small rented farms with indefinite tenure used to raise various crops and animals. For these families kelping, fishing, spinning of linen and military service became important sources of additional revenue.