require to be assessed individually. In addition to the duty of residential tenants and owner-occupiers crofters are required to ensure the croft is cultivated, maintained and not neglected or misused. History Crofting communities were a product of the Highland Clearances (though individual crofts had existed before the clearances). They replaced the farms or bailtean, which had common grazing and arable open fields operated on the run rig system. This change was typically associated with two things. Firstly the tacksmen were steadily eliminated over the last quarter of the 18th century. A tacksman (a member of the daoine uaisle, sometimes described as "gentry" in English) was the holder of a lease or "tack" from the landowner. Where a lease was for a baile, the tacksman usually sublet to the farming tenants and may have provided some management oversight. By preventing this section of society from sub-letting, the landlords obtained all of the rent paid by those who worked the land. Secondly, landowners replaced the older farming methods with pastoral systems. In early cases, these were based on cattle. Much more common was the introduction of extensive sheep farms. In many clearances, the tenants of inland farms were moved to crofting communities in coastal areas, leaving the land they had left for sheep. This type of clearance was carried out mostly until the 1820s. The crofts created by clearance were not intended to support all the needs of those who lived there and consequently were restricted in size to a few acres of arable land with surrounding shared grazing. Landlords intended their crofting tenants to work in various industries, such as fishing or kelp. A contemporary estimate was that a crofter needed to carry out 200 days of work away from his croft in order to avoid destitution. In the second half of the 19th century, many crofters provided a substantial migrant workforce, especially for lowland farms. Crofting communities were badly hit by the Highland Potato Famine. The small arable plots had meant that the potato was an essential crop, due to its high productivity. The arrival of potato blight (and the collapse of the kelp industry a few years before) made some crofting communities inviable. This gave rise to the second phase of the Highland Clearances, when many tenants left the Highlands, often emigrating. In the 21st century, crofting is found predominantly in the rural Western and Northern Isles and in