The National Union of Dock Labourers (NUDL) was a trade union

Trade union

A trade union, trades union or labor union is an organization of workers that have banded together to achieve common goals such as better working conditions. The trade union, through its leadership, bargains with the employer on behalf of union members and negotiates labour contracts with...

 in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. It was formed in Glasgow

Glasgow

Glasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands...

 in 1889 but moved its headquarters to Liverpool

Liverpool

Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...

 within a few years and was thereafter most closely associated with Merseyside

Merseyside

Merseyside is a metropolitan county in North West England, with a population of 1,365,900. It encompasses the metropolitan area centred on both banks of the lower reaches of the Mersey Estuary, and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirral, and the city of Liverpool...

. The union retained a strong presence in a number of Scottish ports but closed its Glasgow branch in 1910 and was replaced locally by the Scottish Union of Dock Labourers

Scottish Union of Dock Labourers

The Scottish Union of Dock Labourers was a Glasgow-based trade union for waterfront workers. It was formed during the seamen's and dockers' strikes of June-July 1911. It replaced the National Union of Dock Labourers, which had been formed in Glasgow in 1889 but later became unpopular in that port,...

, which was formed during the seamen

National Union of Seamen

The National Union of Seamen was the principal trade union of merchant seafarers in the United Kingdom from the late 1880s to 1990. In 1990, the union amalgamated with the National Union of Railwaymen to form the National Union of Rail, Maritime and Transport Workers .- The National Amalgamated...

's and dockers strikes of 1911.