Grey Wagtails breed in the Atlantic Islands, northwest Africa and across southern Europe north to parts of Fenno-Scania. They are absent from Europe east of the Carpathians but reappear from the Urals across Asia to Kamchatka and Japan.They also occur from Turkey through the Caucasus to Iran. Some southern and western populations are resident, while others migrate to central Africa, Arabia, the Indian subcontinent and southest Asia.
    In Britain Grey Wagtails were largely restricted to Scotland and northern England until the 1830s when they started to expand southwards, reaching into northern England and Wales by the end of the 19th century and eastern and southern England by the 1950s. Bird Atlas 2007-2011 recorded a 19% expansion of breeding season distribution since the 1968-72 Breeding Atlas and a 38% winter range expansion since the 1981-84 Winter Atlas.
    In Wiltshire they first began appearing in winter in the mid-19th century. The first recorded breeding occurred in the Marlborough area in 1867 and there were occasional reports from the same area into the first quarter of the 20th century. By the 1950s the species was being described as well distributed in the county; breeding was said to be not uncommon. They were knocked back by the harsh winter of 1962-63, but had recovered by1969 and continued to expand in range and numbers, in line with the national trend of expansion from the north into southern counties. Birds of Wiltshire recorded them in 207 tetrads with breeding in 97. WTA2 recorded them in 201 tetrads with breeding in 101.

The following references are used throughout these species accounts, in the abbreviated form given in quotation marks:
1968-72 Breeding Atlas” – Sharrack, J.T.R. 1976:  The Atlas of Breeding Birds in Britain and Ireland. T. & A. Poyser
1981-84 Winter Atlas” – Lack, P.C. 1986:  The Atlas of Wintering Birds in Britain and Ireland. T. & A. Poyser
1988-91 Breeding Atlas” – Gibbons, D.W., Reid, J.B. & Chapman, R.A. 1993: The New Atlas of Breeding Birds in Britain and Ireland 1988-91. T. & A. Poyser
Birds of Wiltshire” – Ferguson-Lees, I.J. et al. 2007 : Birds of Wiltshire, published by the tetrad atlas group of the Wiltshire Ornithological Society after mapping fieldwork 1995-2000. Wiltshire Ornithological Society.
Bird Atlas 2007-2011” – Balmer, D.E., Gillings, S., Caffrey, B.J., Swann, R.L., Downie, I.S. and Fuller, R.J. 2013: Bird Atlas 2007-2011: the Breeding and Wintering Birds of Britain and Ireland
“WTA2” – ("Wiltshire Tetrad Atlas 2 ") the present electronic publication, bringing together the Wiltshire data from “Birds of Wiltshire” and “Bird Atlas 2007-11”, together with data from further fieldwork carried out in 2011 and 2012.
"Hobby" - the annual bird report of the Wiltshire Ornithological Society.