At one point in the early 1900s a fifth of all ships in the world were made on the River Clyde in Glasgow.

The city's location and its proximity to steel and other raw materials needed for shipbuilding ensured the industry boomed and, at its peak, employed a workforce of tens of thousands.

A century later, just a few thousand jobs remain at the Govan and Scotstoun shipyards.

Today's announcement will slash that number again and further erode what was once one of Scotland's greatest sources of pride.

Dr Phillips O'Brien, a history lecturer at Glasgow University, said: "The sad fact is that the decline has almost already happened. We talk about Glasgow as a great shipbuilding city but it is now a relatively small shipbuilding city.

"It built more ships than any city in the world at different points and employed many tens of thousands of people but the decline that set in from the Second World War has erased almost all of that."

Around 30,000 ships were built on the Clyde over the 19th and 20th centuries.

The shipyards that lined the river played a vital role in the First and Second World War efforts, with Clydebank paying the price with heavy Luftwaffe bombing in 1941.

In the decades that followed, Glasgow's shipbuilding industry could no longer compete with production in other countries.

The major yards began to be closed but not before the construction of one of their most famous liners, the QE2, in 1968.

The Clyde yards were thrust into the limelight around the world in the early 1970s with the Upper Clyde Shipbuilders (UCS) work-in.

It was in response to the Conservative Government's plan to shut the yards on the Clyde, which would have cost 6,000 jobs.

But rather than a strike or a sit-in, the leaders of the unions at UCS instead decided that they could show that the shipyards were viable by locking out management so the workers could complete the orders themselves.

In the end Edward Heath's government backed down and the yards were saved.

Jimmy Reid, a working-class hero from Govan, became the spokesman for this work-in and his eloquence and passion earned him an international profile and a place in Scottish history. His most-famous rousing speech was broadcast around the world.

But the decline had already started.

Dr O'Brien said: "It became relatively too expensive to make ships here.

"Much of the work began shifting to Asia at the beginning of the 1950s and 60s; originally to the Japanese shipyards, now the Korean and Chinese shipyards.

"There have been some European success stories however. The Germans still build a certain amount of ships.

"What Glasgow has been left with is making warships for the British Government which will pay the Glasgow price as opposed to, say, the Asian price per tonnage."

The financial services sector in Glasgow now employs around 10 times the number of people in shipbuilding, but any threat to jobs on the Clyde still provokes a strong emotional, and political, response.

"If you look at shipbuilding jobs within the context of the Scottish economy, even the Glasgow economy, the numbers are not as large as one might think," said Dr O'Brien.

"But there's something very politically resonant about the shipbuilding industry. Crucially, they are well-paid industrial jobs and what we have seen over the last few decades throughout much of the world, and certainly Britain, is the decline of industry and the rise of service jobs.

"So having those well-paid industrial jobs is important as they are some of the few that are left."