A combined 100 years in the sex trade: Meet the world's oldest prostitutes.

Meet the twin sisters who are believed to be the world's oldest sex workers.

For more than 50 years each in the sex trade, Louise and Martine Fokkens worked as prostitutes in Amsterdam. The pair, now in their 80s, have since retired — ending an illustrious career filled with interesting stories.

Their journeys began back when they were in their early 20s. Both started working in the sex industry as a means of survival. 

Louise told The Guardian that she initially starting sex work because her abusive husband forced her to. Later on, she would stock some of the money she had made and used it to make a fresh start for herself.

"I was beaten on to the streets by my husband in my early 20s. He told me unless I earned money for him he would leave me, and I had children and loved him, so I had to do it," Louise explained.

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Soon after Louise found her feet in the industry, Martine joined her.

"We are always together. We do everything together," the duo said.

Louise has three children from her previous relationship, and said some or all of them have been in and out of foster care. Martine has four children, and has said her familial story is not dissimilar to her sister's. Louise and Martine were also ostracised from their parents after they found out what their daughters were doing.

"Our mother drove down to the canal where we were working on the street and shouted: 'I see you! Your father is coming.' She hit me. I was very embarrassed for my parents." 

For people who have interviewed Louise and Martine, they say the twins are not only alike physically, but in their mannerisms too.

One journalist said: "The sisters dress and speak identically, and, to complicate matters, often talk over each other, in a way that is almost impossible to understand. They seem to speak in a kind of code."

In 2011, the sisters were featured in a documentary called Meet the Fokkens, which followed their lives working in the red-light district in Amsterdam. 

The two sisters, Louise and Martine Fokkens. Image: Meet the Fokkens documentary/Kino Lorber. 

In the documentary, the sisters said they had in total slept with more than 335,000 men.

As for their life lessons learned along the way, the duo didn't have advice specific to the sex work industry or their own pleasure, but rather what they've learned about what men generally 'like'. 

"Be easy, listen to what he wants — always," Louise previously told MailOnline. "When we started in the 1960s, we learned the same thing from the older women we worked with. Every man wants something different and that's the real game — finding out what they want."

The twins never foresaw themselves staying in the industry for so many decades. But after becoming a bit of an institution in the red-light district and gaining popularity, they ultimately found a great level of success. As for what led them to retire in their 70s, Louise said a declining client base and advancing arthritis was impairing their ability to work. Martine told The Inquisitr that she still has one regular client she sees.

"I couldn't give him up. He's been coming to me for so long like it's like going to church on a Sunday."

Interestingly, Louise and Martine both see their early days in sex work as "the golden years", believing the industry now isn't what it used to be.

"It is very different now. We used to sit in the windows with clothes on. Today they are totally naked. There are few Dutch women and no sense of community these days," said Louise to The Inquisitr.

Martine added in the same interview: "The legalisation of brothels in 2000 has not improved prostitutes' lives. There is no point working just for tax. That is why the girls are working from the internet and from home — you are less likely to be spotted by the taxman. It is better for the pimps and the foreigners, but not for the Dutch girls."

Ultimately, both sisters say they look back fondly on their time doing sex work. 

"Everything's plastic today," said Louise to the UnClogged in Amsterdam blog. "But we're the real thing, honey. We know the tricks and how to make the customers laugh, too."

Feature Image: Meet the Fokkens documentary/Kino Lorber.