Gen. Charles de Gaulle reviews sailors of the Free French forces at Wellington Barracks in London on July 14, 1942. Czechs, Norwegians, Poles and others also fled to Britain during World War II. (STF/AFP/Getty Images)

Paul Kennedy is a professor of history at Yale University and author of “The Rise and Fall of the Great Powers.” He is completing his new book, “Victory at Sea, 1936-1946.”

On June 18, 1940, a day after Marshal Petain’s France surrendered, with a battered British army home from Dunkirk and the first German armored columns reaching the Channel, the great political cartoonist David Low sketched a wonderful image of a defiant British soldier standing on the rocky shores of Kent, fist in the air, daring the Third Reich to advance and be pounded. The title of this classic picture was “Very Well, Alone.” It was a hugely popular cartoon in a nation bruised by so much bad news yet also brought up on a long history of fighting larger foes — Philip II, Louis XIV, Napoleon, the Kaiser — and prevailing. Isolated, defiant, still dangerous, come the four corners of the world in arms, Britain could take it.

But neither the defiant British soldier, nor Britain itself, stood all alone in that summer of 1940. Not only was the island-state to be joined and reinforced by the soldiers, ships and air squadrons of the British Empire-Commonwealth, but it was also joined, almost immediately, by an unusual flood of smaller European allies. The latter, as the author Lynne Olson shows in “Last Hope Island,” were a very mixed bag indeed; they included European monarchs, governments, political outsiders, soldiers, pilots, cryptographers, merchant skippers and their ships, all of whom had escaped to Britain after their countries were conquered by the Nazis and now wished to stand and fight. Among them could be counted the gallant King Haakon of Norway, a group of motley Free Czech pilots, and Polish professors of mathematics and engineering, unified only by their desire to continue to battle, their loathing of Germans and of any of their countrymen who collaborated with them, and their deep gratitude to Britain.

Enjoying Winston Churchill’s political protection — the prime minister was way ahead of his advisers in seeing these survivor groups as potentially invaluable assets — they were variously settled into empty barracks, elegant townhouses, seaside hostels and places in the country while they recovered and tried to find their feet again.

"Last Hope Island: Britain, Occupied Europe, and the Brotherhood That Helped Turn the Tide of War," by Lynne Olson (Random House)

Certain of these refugee groups have had their stories told before. Charles de Gaulle’s testy four years of exile in Britain is the best-known of these tales, and certain European countries cherish the stories of their national resistance’s London links, but Olson’s book is the first to weave this all together. A passionate anglophile and London-lover, Olson is thrilled by the individual heroism, spunk and sheer ingenuity of so many of these survivor organizations, and marvels at the efforts each made in the common struggle. It’s a well-written and well-illustrated book, and deeply researched. It hops from one vignette to another, from a social account of a London reception of Polish aviators to a gripping story of some bloody resistance in France.

Given the liveliness and occasional breathlessness of Olson’s account, it may be sometimes difficult for the reader, or even the military historian, to understand what exactly these varied bodies of French, Belgians, Danes, Dutch, Norwegians, Czechs and Poles did “that helped turn the tide of war” (as the book’s subtitle has it). Boosting British morale on the home front, to be sure, and later blowing up a railway bridge in France, maybe; but is there a better and more solid measure of how the exiled forces contributed, some small, some rather more, to the eventual victory?

Well, yes. The Norwegians brought a resistance that stretched the German army across Norway, plus a vast merchant navy of 1,300 vessels, the fourth-largest in the world. The French not only brought the nearly insufferable de Gaulle but also the later Free French Army, and in time an even larger resistance movement. The Poles brought a double benefit: the inestimable value of the early Enigma machines and cryptologists who (scarcely known even to British intelligence) helped crack German codes, and hundreds of Polish airmen, including those redoubtable Hurricane squadrons that performed so well in the Battle of Britain. None of this, individually or collectively, turned the tide of the war — that’s an incorrect way to think of it. What they did, in small though critical ways, was to assist Churchill’s Britain during that critical period after the fall of France when its most important strategic task was simply to continue to fight and not to fall. Within another year, Hitler had committed the colossal blunder of also going to war against Russia; six months later, he rashly declared war on America.

From January 1942 onward, Churchill’s many little European allies fought on, in the air, at sea, in the hedgerows of France and the mountains of Greece, even if the prime minister paid ever less attention to them (or so they felt) and more to Stalin and Roosevelt. And when the fighting ended, they returned home, restored their monarchies or suffered communist takeovers, savagely punished collaborators, and sought to preserve their wartime affection for a British nation that had taken in strangers.

It’s a lovely story, fondly told by Olson. It is true that she often makes the various wartime contributions weightier than they actually were. And she pushes it too much by hinting that a future European union came out of this wartime bonding. She is sad — which is also true of this reviewer — that much of the tale is now lost and, worse still, that in this age of Brexit, an ignorant nationalism has replaced this earlier generosity and steadfastness. Once again, it seems, Britain stands in some awkward and fearful relationship to its European neighbors, even to Dutchmen and Poles who were its greatest admirers. Maybe, perhaps, in another decade, this will turn again. In the meantime, “Last Hope Island” is a book to be welcomed, both for the past it recovers and also, quite simply, for being such a pleasant tome to read.

Last Hope Island
Britain, Occupied Europe, and the Brotherhood That Helped Turn the Tideof War

By Lynne Olson

Random House. 553 pp. $30