Recently, while looking into how the bodies of world leaders are preserved, I came across a truly fascinating story. In fact, there are only 5 leaders’ bodies in the world that are still preserved permanently, and behind this are complex interwoven choices shaped by technology and by the times.

Lenin was the first pioneer. When he died in 1924, he was originally supposed to be buried normally, but the public’s overwhelming fervor for mourning was so intense that, after his body began to deteriorate, it was suddenly decided to preserve it by freezing. Soviet scientists then began serious research from there—developing a special embalming fluid and establishing techniques to suppress the growth of bacteria by replacing the water in the human body. Lenin’s tomb is equipped with a constant-temperature cooling system, and even today, laboratory specialists reportedly carry out weekly restorations and regular maintenance, so it really takes a lot of effort.

But when it comes to Stalin’s body, everything changes. Even though he was another Soviet leader, Stalin’s body—placed in Lenin’s tomb in 1953—no longer matched the values of the leadership at the time by 1961, and it was cremated. It’s a truly symbolic example of how the choices of an era can have a decisive impact on the preservation of a body.

It seems Ho Chi Minh in Vietnam wanted to be cremated during his lifetime, but his successors decided to preserve him. During the Vietnam War, his body was secretly kept in a mountain cave for 5 years, and Soviet experts carried out embalming procedures in the cave while avoiding bombings—so it must have been a really difficult task.

In the case of Nétu of Angola, there were even more technical challenges. There was the problem that pigmentation in Black skin would leak out, so Soviet specialists went so far as to develop a pigment-preservation technique. These days, his body is reportedly shown to the public only once a year on his birthday.

There are also failure cases. Gottwald’s body was cremated after it decayed in 1962 because the embalming technology was insufficient. Dīmitrof was preserved for over 40 years, but due to political changes in Eastern Europe, he was cremated and buried in a cemetery. The body of Joba Mountain in Mongolia was also cremated after the mausoleum was destroyed in 2005, in accordance with Buddhist rituals.

When you think about it—this includes the fate of Stalin’s body—these cases show just how large a role politics and the flow of history play, not just technology. The bodies in crystal coffins certainly prove the achievements of embalming technology, but at the same time, they are also a mirror of history.