- The cod wars -

The long-running "Cod Wars" between Britain and Iceland began in 1958 and broke out again in 1972 and 1975.

The violent clashes saw Royal Navy warships escort British trawlers into disputed wars around the fish-rich North Atlantic island.

Icelandic patrol boats would regularly cut British nets and confrontations often ended in vessels ramming each other on the high seas.

Iceland finally emerged victorious in 1976 after a NATO-brokered agreement that saw it win a 12-mile (22-kilometre) limit where only its boats could fish and a 200-mile zone where foreign fleets needed permission to fish.

The deal led to thousands of job losses in the UK and ended more than 500 years of unrestricted British fishing there.

- The mackerel war -

The "mackerel war", which began in 2010, again pitted Britain against Iceland, with Scottish politicians calling for a blockade of ships from the island in a row about over-fishing.

The European Union backed British fishermen, condemning both Iceland and the Faroe Islands for unilaterally tripling their quotas of the fish.

The dispute helped scuttle Iceland's bid to join the EU and led to tensions with EU member Denmark over the Faroes. Although Danish, the islands between Britain and Iceland are autonomous.

- Brexit adds to French tensions -

Prime Minister Boris Johnson's pledge to reclaim "full control" of British waters clashes with the EU's insistence on upholding existing agreements following the UK voting to leave the bloc in 2016.

Britain deems the current mechanism for sharing fishing quotas "outdated" and says access should be negotiated annually.

French fishermen feel particularly threatened by Brexit, with nearly a third of their income coming from fish caught in British waters.

Fisherman in France's busiest English Channel ports including Dunkirk and Boulogne-sur-Mer have begun attempting to block trucks trying to bring in catches from Britain.

They say the post-Brexit accord is a "sham" and that the UK has only granted licences to 101 of the 203 French boats looking to fish between six and 12 nautical miles from the British coast.

- The scallop wars -

The dispute adds to the long-simmering conflict between Britain and France over the prized molluscs off Normandy which has periodically turned violent over the last decade.

French fishermen were incensed that British scallop boats could access the bay of the Seine River when they could not, with boats being rammed and stoned in several clashes between 2012 and 2018.

- King's 1666 Belgium deal -

As with Dutch and Danish fleets, Belgian boats complain they will come out of the post-Brexit situation worse off as fish retreat north with global warming.

Flemish fishermen feel particularly aggrieved as they were granted the right to send 50 boats to fish off England in perpetuity by King Charles II in 1666 after the grateful English monarch spent part of his long exile in the Low Countries.

More than half of the Belgian fleet's revenue comes from fish caught off England.

- Ireland -

Around half of Ireland's catch also comes from UK waters, according to the Irish Department of Food, Agriculture and the Marine.

Irish boats fear being locked out of waters that they have fished for centuries before either Ireland or Britain joined the EU.