The Heligoland Mandate

A curious snippet from Margaret MacMillan's account of the Paris Peace Conference, Peacemakers (2002):

Why not give it to Hughes of Australia, suggested Clemenceau.1

The 'it' was Heligoland, a small island in the North Sea, off the north-western coast of Germany. For most of the 19th century it had belonged to Britain, which swapped it for Zanzibar to Germany in 1890 -- when relations between the two countries were still friendly. But then the naval arms race started up, and Heligoland became a handy place from any attempt by the Royal Navy to approach the German coast could be interfered with. Which is why, in Paris in 1919, the question arose of what to do about it.

The Admiralty naturally wanted the island back, but presumed that the Americans would object. In the end, the compromise solution adopted was to destroy all of its fortifications. Presumably Clemenceau's suggestion was that Australia, as a nation almost as far away from Heligoland as possible, be given a Mandate over Heligoland (to add to New Guinea and Nauru), so that neither Britain nor Germany would have control over the disputed territory. I don't know how seriously he meant it, or whether it ever had a chance of getting up. But in my mind's eye I could see Australia dominating the North Sea from its Heligoland base with our single battlecruiser ... well, no. But what would have happened if Australia had been given a Mandate over Heligoland?

Well, for a start, I don't think Australia would have been exactly regarded as a disinterested party by Germany: British Empire and all that. In practice, there probably wouldn't have been much difference between Australia governing Heligoland and Britain governing it: precisely because we were so far away from Europe, we had nothing to gain from it and nothing to lose, except perhaps in terms of our international reputation. I don't see any reason why we wouldn't use it to benefit our friend (and protecting power), Britain, in whatever way they wished.

What use would it have been to Britain? MacMillan notes that the coming of the aeroplane was another reason why Heligoland seemed newly valuable. She doesn't explain, but seems to imply that this is because of their potential use as airbases for offensive action. I doubt that it would have been of much use for Britain in this way -- it was too small to have a really big airbase (only 1 sq. km!) to be very powerful, and too close to Germany (only 70 km away) to survive for long.

But what Heligoland might have been very useful for was as a RDF (radar) station, to give Britain early warning of an incoming knock-out blow. It was actually ideally placed for this purpose.

Distances from the frontiers of heavily-armed air powers to the British coast

This map, taken from The Chosen Instrument (1938) by Norman Macmillan (no relation, as far as I'm aware), shows the ranges from the various 'heavily-armed air powers' (France, Germany, Italy) to Britain. I've marked the rough range of a hypothetical Chain Home RDF station on Heligoland in red: it covers the entire German north-west coastline very handily.2 So, assuming the Luftwaffe respected Dutch neutrality, any bombers they sent to Britain would have to pass through Heligoland's detection radius. Heligoland could then give warning to London that a knock-out blow was imminent. At the cruising speed of a He 111, and depending on the flight path, that could be 1.5-2 hours additional warning (or even more if the bombers formed up in range of Heligoland). Very handy, even though the actual targets wouldn't be known until the English coast was crossed.

Obviously, there are a whole bunch of caveats. I'm obviously assuming that, not only is Dutch neutrality respected (and the Low Countries not invaded, for that matter), but also that France has not been conquered. This is not our 1940, in other words, but a scenario often envisaged in the 1930s, where Germany suddenly attacks Britain without any warning. I'm also assuming that Germany doesn't assault Heligoland first, or cut its communications with Britain (whether radio or cable).3 But even these acts would at least give warning that an attack was imminent, which is more than the British got in the usual nightmare imaginings. Finally, and perhaps least reasonably, I'm assuming that Britain (well, Australia) would not have handed it back to Germany. Heligoland in foreign hands would have been a major irritant to German nationalists, and unlike the case with the ex-German colonies, Hitler wouldn't have been merely posturing when he said he wanted it back. So, very likely, giving it back to Germany would probably have been one of the first acts of appeasement.

The only reason to keep it, frankly, would be as an early warning post. Even then, would the Air Ministry risk placing such a valuable piece of technology as radar right under the German's noses, where they could study its emissions at their leisure and quickly capture it in wartime?4 Probably not. Though even without RDF (which in any case was secret until 1941), the British public might gain some measure of confidence, whether false or not, just from being told that there were 'observers' on Heligoland who would give advance warning of a massive aerial armada heading their way.

Still, it would seem that, even in this alternate history, the Heligoland Mandate would have come to exactly nothing in the end, just as it did in ours. An interesting and diverting nothing, though.

Image source: Norman Macmillan, The Chosen Instrument (London: John Lane The Bodley Head, 1938), 21.

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  1. Margaret MacMillan, Peacemakers: The Paris Conference of 1919 and Its Attempt to End War (London: John Murray, 2002), 187. []
  2. Chain Home Low, for detecting low-level aircraft, had a much shorter range. But it would still cover a useful area of sea. []
  3. Another thought: a German army which had prepared for an opposed landing on Heligoland might also be a bit better prepared for an opposed landing in Kent ... []
  4. Germany had radar too, of course, but they did not well understand the capabilities of the British system or how it would be used -- even after the Graf Zeppelin II made several trips parallel to the English coast, loaded with radio detection gear, in what must have been among the first ELINT air missions ever. []

8 thoughts on “The Heligoland Mandate

  1. The fortifications were eventually flattened after the second world war, in what was the biggest conventional explosion then known.

  2. Post author

    Yes -- flattened again, that is: the Nazis rebuilt them after the Wilhelmine ones were blown up. According to Wikipedia, the post-WWII explosion appreciably altered the island's shape!

  3. Chris Williams

    Brickhill's _Dambusters_ claims that 617 squadron did a pretty good job of flattening (or at least denting beyond repair) them some time in the early Spring of 1945: like a lot of events, this points out the way the Bomber Command got the hang of just when it no longer mattered.

  4. jason

    What makes you think the radar station would have survived much past the opening day of the war? They would have known full well its value as an early warning post. Frankly I think that the Germans would have devoted quite a bit of thought to knocking it out. Either by aerial bombardment, a commando operation, or a simple amphibious invasion. It's not like the Brits could have stationed a serious number of troops there to defend it.

  5. Post author

    You're quite right, but I do actually address this in the post. (Third-last paragraph.) I may not have made it sufficiently clear that my analysis is not set in the context of the sort of air war that was actually fought in 1939-41, but the one which was widely feared before 1939. That is that Germany would attempt to deliver a knock-out blow by a massive aerial attack on London right at the start of the war -- in fact, most likely before war had been declared. Many books in the 1930s argued that modern bombers would only take 10 minutes (or whatever) to cross from the coast to London, which was not long enough for interceptors to take off and rise to a sufficient height to engage before the raid reached its target. (This was an important reason why, so it was believed, the bomber will always get through.) So, I'm arguing that Heligoland could have been a tripwire which might have provided some psychological reassurance, at least, that a massively destructive air raid could not come with no warning: at the very least, an attack on or silencing of the British base there would be a sign that a knock-out blow was imminent, and that ARP and air defence measures should be implemented at once.

  6. Clotario

    The issue of giving Helgoland away was debated by the British government. It was decided that Helgoland was essentially useless as a military installation - once war came it would be impossible to fortify it and if done prior to war it would sour relations. No win.

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