The Mystery of the Eels
The legend comes first. It is followed by what later generations made of it, what can be verified, and what remains open.
The legend
On a dark autumn night in 1666, the eel trader Adriaan Focke follows the eels down the Eider, westwards towards Friedrichstadt, as he returns from the Rendsburg market. A westerly storm tears the mainsail, but the foresail alone keeps his boat under control until it runs aground at the Grönsfurt near Fockbek. The next morning, by the Fockbeker See, he watches the village try to execute a supposed thief of herrings by drowning, and sees the eel swim away.
„De Aal swemmt wieder. De geiht blots na Huus.“
In English: The eel swims on. It is only going home.
When the eels move on, Adriaan stays behind and says:
„Wer weten will, wo de Aal herkümmt, mutt dor blieven, wo he vörbitreckt.“
In English: Whoever wishes to know where the eel comes from must stay where it passes.
He establishes an eel trade in Fockbek, remains despite the mockery of the Rendsburg merchants, and in the spring of 1667 receives the honorary name Aad Fock from the village assembly of farmers, as told in “The Eel That Survived Its Own Execution”.
Three readings
Three voices from three periods read the same story in their own ways.
A right held for the poor
Claus Aad Fock, nineteenth century, as handed down by Grete
Claus is said to have observed that the people of Fockbek had no right to keep the eel. Under an old right, the lake and its fish belonged to the town of Rendsburg for the benefit of its poor. That was why the lake was called Armensee. Returning the eel to the water was the only thing the people of Fockbek were allowed to do. The mockery from Rendsburg also belonged to the long dispute over the fishing right.
Claus added, drily, that the lake was not even two metres deep at its deepest point.
What returns
Grete Aad Fock, twentieth century
To Grete, the eel, the word Fock, and the house had one thing in common: one does not see where they come from, only that they return. That is why the house keeps no family tree. In her reading, the name is not inherited like blood. It reappears in every age, as the eel reappears in the lake.
Grete recognised the same pattern in all the later stories. Something was always meant to sink, and it always swam on.
A fitting night
Editor’s note, 2026
Eel Night is handed down as the night of 17 to 18 October 1666 in the Julian calendar then in use in Schleswig. It agrees with what is now known about silver eels. They travel to the sea at night in autumn, especially during storms, with rising floodwater, and around the new moon. Calculation shows that the evening of 17 October was a new moon. In today’s calendar, the date was 27 October.
Adriaan’s last words about the eels coming from far away anticipate what research proposed in 1922 and tracked with transmitters in 2022. Europe’s eels travel some 6,000 kilometres to spawn in the Sargasso Sea. No one has yet seen them spawning there.
What the record shows
Only verifiable facts are given here. They do not prove the legend, but they show the true background to the eel question.
| Year | The eel question |
|---|---|
| c. 350 BC | Aristotle holds that eels arise from the “entrails of the earth”. |
| 1495 | A memorial book records Rendsburg’s fishing right in the Armensee “for the benefit of the poor in the almshouses”. |
| 1666 | The evening of 17 October in the Julian calendar is a new moon. This has been calculated. |
| 1700 | Schleswig and Holstein change from the Julian to the Gregorian calendar. |
| 1876 | In Trieste, Sigmund Freud dissects 400 eels in search of their reproductive organs, without success. |
| 1904 to 1922 | Johannes Schmidt searches for the spawning ground and in 1922 finds the smallest eel larvae in the Sargasso Sea. |
| 1989 | The Fockbeker See ceases to be part of the municipal territory of Rendsburg. |
| 2022 | For the first time, adult eels carrying satellite tags are tracked as far as the Sargasso Sea. |
- The Fockbek account of Aalversupen tells of the herrings placed in the lake and the eel that escapes its execution: Municipality of Fockbek: “De Aalversuper” (in German).
- A herring and an eel appear in Fockbek’s municipal coat of arms and recall the tale: Wikipedia: “Fockbek” (in German).
- The memorial book of 1495, the fishing right held for the poor, the dispute from the sixteenth century, the lake’s inclusion within Rendsburg’s municipal territory until 1989, and its depth of 1.9 metres are recorded for the Armensee: Wikipedia: “Armensee” (in German).
- Silver eels migrate at night from September to November, particularly on rough and stormy nights, with rising floodwater, and around the new moon: Anglermap fish encyclopaedia: “Aal: Lebensweise” (in German).
- The calculation of the new moon on 17 October 1666 in the Julian calendar, 27 October in the Gregorian calendar, follows Jean Meeus’s method in Astronomical Algorithms; Schleswig and Holstein made the calendar change in 1700: Society for Schleswig-Holstein History: “Kalenderverbesserung” (in German).
- Aristotle wrote of eels arising from the “entrails of the earth”, and in 1876 Sigmund Freud dissected 400 eels in an unsuccessful search for male reproductive organs: Discover Wildlife: “It lasted thousands of years and puzzled Aristotle and Freud – is this the biggest animal mystery of all time?”.
- Johannes Schmidt began his expeditions in 1904 and in 1922 found the smallest eel larvae in the Sargasso Sea south of Bermuda: Wikipedia: “Johannes Schmidt (Biologe)” (in German).
- In 2022, researchers obtained the first direct evidence of adult eels travelling towards the Sargasso Sea; neither eggs nor spawning animals have been found there: Scientific Reports: “First direct evidence of adult European eels migrating to their breeding place in the Sargasso Sea”.
- The word Fock is attested in Middle Low German from about 1500, is related to its Middle Dutch and Dutch counterparts, and has a disputed origin: DWDS: “Fock” (in German).
- The European eel is threatened with extinction: Phys.org: “Ancient mystery of European eel migration”.
The return
Every later story repeats the same pattern: something is meant to go under and swims on. Wiebke remains through the flood. Claus loses everything twice and rebuilds three times. Grete twice sells the inn and keeps it. The papers are never printed, yet appear in 2026. Grete was the first to notice this return. Die Überlieferung (in German) tells of the bearers of the name, while the Fockbeker Blätter tell their stories.
The open riddle
„Se kaamt vun wiet her.“
In English: They come from far away.
What did Adriaan mean by “wiet her”, and how did he know? Why did he never follow the eels farther, although they were the reason for his journey? Research, too, leaves the last part of the question open, for no one has yet seen eels spawning.
Eel Night
Adriaan’s walk to the Grönsfurt became a custom. The present bearer observes it: on the first dark and stormy night of autumn, he goes to a body of water, preferably the Eider, and speaks the motto. Anyone who accepts the name does this for the first time on the next Eel Night.