SEOUL - Fifty years ago, several hundred South Koreans went to work in German mines - the first wave of a flood of Korean migrants whose remittances helped jumpstart one of the great economic transformations of the modern age.
The experience was often lonely, and for some their contribution was tainted on their return by the social stigma attached to a job that was tough, filthy and dangerous in a society that looked down on manual labour.
As a result, they feel their role in South Korean history has been largely overlooked, despite helping to seed South Korea's economic growth and rapid industrialisation by sending funds home.
Mostly in their 20s, the miners - the first South Koreans to work overseas since the peninsula split into the capitalist South and a communist North in 1945 - were part of Seoul's strategy to solve a high jobless rate and earn hard foreign currency.
Bae Jung-Hwan left his homeland in 1970 to work at a German mine before returning a few years later. He says he only recently told his wife and children about his past.
"As the youngest child of a poor family with five sons and daughters, the high-paying job in a German mine was an inevitable choice," said Bae, who now runs a private educational institute in Seoul.
"But the work there was tough beyond my imagination," he added.
For up to 12 hours daily, Bae carried about 50 kilograms of rock in a drift 1,200 metres below the surface in temperatures of more than 30 degrees Celsius.
"I once worked despite breaking my middle finger because I needed to save money for my family and studies," he said.
After three years, he returned home and completed his education to become a high school teacher, reluctant to address his past in a competitive society that respected academic scholarship but looked down on those performing what were considered menial tasks.
"Due to social prejudices against miners, I had not spoken about my experience in Germany to my friends, school colleagues and family," Bae said.
"But I'm not ashamed of my work in Germany any more as it helped me become a stronger person and overcome all hardships throughout my life," he said.