When the Channel Islands were deemed indefensible by Winston Churchill, their occupation by the Germans became an inevitability.
Hitler wanted the Channel Islands to be an 'impregnable fortress'
Adolf Hitler saw the five islands of Jersey, Guernsey, Alderney, Sark and Herm as a strategic landing stage for an invasion of mainland France.
But it was precisely because of this precarious location on the edge of the Normandy coast that Churchill believed them to be beyond the scope of his armed forces.
Thus despite early acts of heroism and efforts to save Allied forces stranded off the French coast, the people of the islands were left completely defenceless.
By May 1940 it became increasingly clear that the islands lay directly in the path of the advancing German forces.
Islanders had to make the agonising decision of whether to stay or to leave their homes and possessions and flee to England.
Fearful of the impending invasion some 23,000 queued in St Helier for days to register for evacuation - but only a handful of boats were available to take fleeing islanders to the mainland.
And when the boats stopped coming those who remained had to return to their homes to prepare for the German assault.
In the end only 7,000 islanders left after Jersey's Bailiff revealed in a rousing speech that they had been effectively abandoned to the coming invasion.
By 1 July 1940 the Germans had arrived and they were astonished to find the islands undefended.
The occupying troops demanded white crosses of surrender be painted in prominent places.
The islands' senior crown officers went to meet the invading forces and swastikas were soon draped from town halls.
The Germans took over the government and the courts, and passed new laws enforcing the occupation and its ideology.
A register of the island's Jews was created and all Jewish businesses had to display a yellow notice.
The Germans soon began a fortification of the islands.
Hitler became obsessed with the idea that Britain would try to recapture the islands and issued a personal directive that they be turned into an "impregnable fortress".
A fifth of all the defence works in the so-called Atlantic Wall - a defensive line stretching from the Baltic to the Spanish Frontier - were built on the Channel Islands.
Much of the work was carried out by Organisation Todt - which used up to 6,000 slave workers - mainly Russians and Spanish Republicans.
British Intelligence estimates that four out of 10 of these workers died.
To enforce the occupation the Germans restricted movement, forced those over 14 to carry ID cards and imposed a curfew.
Only one thoroughly censored newspaper was allowed on the islands and radios were confiscated. Listening to the BBC on a clandestine set was made punishable by imprisonment.
The RAF dropped information leaflets but possession of these was also a criminal offence.
Cars were requisitioned by the Germans and shipped to the mainland - though some compensation was paid in occupation marks.
The German authorities controlled what farmers grew and in 1940 an inventory of all clothing and goods was drawn up and rationing brought in.
Fisherman were seen as a threat to security, so boats were licensed and low-water fishing could only be carried out in daylight.
While the German occupiers effectively ruled the islands, the civilian administration remained in the hands of a superior council headed by the Bailiff.
This may have been the root of many claims of collaboration.
According to the Jersey Heritage Trust, most islanders were "correct in their dealings with the occupying forces".
Others actively collaborated and informed on their neighbours, it says.
But there is no escaping the fact that more than 1,000 British-born islanders were deported to Germany and many hundreds of others were sent to camps across Europe.
According to historian Dr Philip Sands: "There was absolutely no case of ideological collaboration in the Channel Islands, whereas there was in some other countries.
"In Holland for example, there was a huge Nazi movement there, which was something you did not have at all in the Channel Islands.
"Overall I do analyse Jersey and Guernsey as a case of submission on the grounds of superior force."
The Normandy landings in 1944 heralded the final phase of the of the islands' German occupation.
By August St Malo surrendered and the islands' supply routes were cut off.
For the next eight months, the local population and the 28,000-strong German garrison went close to starvation.
Liberation finally came when an Allied task force headed by HMS Bulldog arrived off St Peter Port, Guernsey on 8 May, 1945.
A declaration of unconditional surrender was signed the following day.