You may not remember Gerd Poppe. In fact, most people have never heard his name, but he was one of democracy’s brave defenders. In the German Democratic Republic (GDR), where Poppe grew up and lived for most of his 84 years, such defenders were desperately needed. Until recently, Poppe’s advocacy for freedom and fair elections in East Germany would have been considered as an important, but historical, chapter, safely consigned to Europe’s past. Now his life, which ended on 29 March, is suddenly far more than that: it’s a guide to how 21st-century citizens of nations sliding towards autocracy ought to live their lives.

When Poppe was born, conditions were, to put it mildly, unfavourable. It was March 1941 and the Second World War was raging. A few months later, Germany invaded the Soviet Union; when Poppe had just turned four, the Red Army reached his home city, where some soldiers exhibited extreme brutality towards the locals.

Matters improved somewhat after Nazi Germany surrendered and the war ended. The massive presence of Soviet occupation troops notwithstanding, the emerging GDR managed to construct a functioning country from what was left over of its part of Germany. In 1959, 18-year-old Poppe won a place studying physics at university in Rostock, and because many things functioned smoothly in East Germany, his graduation five years later was swiftly followed by full-time employment at a semiconductor plant.

Then, in 1968, the Red Army marched into Czechoslovakia, removed the country’s reformist leader and extinguished (or so it thought) Czech pro-democracy sentiments. For East Germans, the Czech experience made three things painfully clear: first, the Soviets and their lackeys in East Berlin would never move towards more democracy in the GDR; second, citizens would have to fight – and take immense risks – to get even a little bit more democracy; and third, their efforts might never bear fruit – but it was important to try anyway.

The 27-year-old Poppe joined dissident circles; he arranged events featuring speakers critical of the regime. In 1975, when he could no longer postpone mandatory military service, he declared that he was a pacifist and, as a result, got assigned to a construction squad. East Germany didn’t force its conscripts to carry out weapons duty, but for those wishing to have a successful career it was unadvisable to serve as a mere construction soldier.

A couple of years later, the East German regime revoked the singer-songwriter Wolf Biermann’s citizenship, and Biermann was barred from the country. The regime had unequivocally communicated that it would tolerate no dissent. In the 50 years since Biermann’s expulsion from his home country, western observers have had the luxury of dissecting East Germans’ response from the safety of their own democratic countries. They’ve often criticised the vast majority of East Germans as too cowardly to protest the expatriation, just as they’ve had the luxury of criticising most Soviet citizens’ lack of courage, most Czechoslovak citizens’ lack of bravery, and indeed that of most people living in autocracies and dictatorships at various points in history.

Poppe’s protest against Biermann’s expatriation had consequences. He was just about to begin a new job at East Berlin’s prestigious Akademie der Wissenschaften when the offer was rescinded; he had to take a job as a swimming-pool attendant instead. The following year, a young scientist named Angela Merkel took up a position at the Akademie. Later, the regime banned Poppe from travelling abroad (not that he’d been able to visit the West anyway) and briefly put him in jail.

Most of those familiar with Poppe like to imagine that they would have been just as brave as he, and quietly condemn Merkel for not having had the courage to speak out. Indeed, for decades dissidents such as Vaclav Havel, Lech Wałęsa and Aleksandr Solzhenitsyn have been celebrated and it has been assumed that we would work up similar courage should it become necessary.

In some countries, democracy is retreating, in some cases at alarming speed. The backsliding will continue until it encounters resistance. The punishment facing those who might do so is not as severe as the punishment meted out on the likes of Poppe, Havel and Solzhenitsyn and many others, but some will have to take that risk.

For decades, westerners have lectured autocracies’ citizens about what they needed to do. Now they can teach us. Poppe left us before he could share his wisdom, some of his fellow advocates for democracy from behind the Iron Curtain are still with us, as are such advocates from other parts of the world. Rather surprisingly, they’ve become an invaluable resource for our times.