At 115 years old, Ethel Caterham from Surrey has lived through an astonishing six monarchs and 27 prime ministers, marking her the oldest human in the world.

Born on August 21, 1909, in Shipton Bellinger in Hampshire, Ethel is the very last known living person to be born in the 1900s decade.

Her life has taken her through two world wars, the first Moon landings, the fall of the Berlin wall, women gaining the right to vote and most recently, Covid-19.

All of which she has survived, but how did she do it?

When asked for her secrets to longevity on her 115th birthday, Ethel said, “Never arguing with anyone. I listen and I do what I like.

“Family is the most important thing in life, to be able to leave memories with your children and grandchildren. Possessions don't matter a bit in the end - all you need is someone to look after you.”

The super-centenarian - a person who is aged 110 or older – has had to witness both her husband, Norman Caterham and their two daughters, Gem and Anne, pass away.

Despite these hardships, Ethel remains well and alive, having three granddaughters that regularly visit her at her care home.

Speaking to BBC Radio Surrey in 2020, Ethel said: 'I've taken everything in my stride, the highs and lows. I've been all over the world, and I've ended up in this lovely home, where everyone is falling over themselves for me, giving me everything I want.'

The secrets to living such a long life comes from a multitude of factors like genetics, social class and ‘even luck,’ chief executive of International Longevity Centre UK explains.

David Sinclair told the Express “there is something about our ability to be resilient that can help you through life like Ethel”.

There is mounting evidence showing specific correlations between higher levels of optimism and healthier behaviours, reduced risk of chronic diseases, and lower mortality, a report by The Longevity Centre says.

Longevity is about 20% genetics and 80% environment, explained Ilaria Bellantuono, director of the healthy lifespan institute at the University of Sheffield.

“It depends on what people make of today's health advancements. If you are smoking, indulging in copious amounts of alcohol and not vaccinating, you will not exceed the average lifespan,” Ilaria stated.

“Those who lived through the war like Ethel, did not have the type of ‘diet or sensory life we have at the moment.

“Specific environmental conditions like no access to red meat and an active life are good for longevity. One is natural selection and the other is the environment.”

The change in physical activity and the physical nature of workplaces will make a big difference to life expectancy nowadays, David Sinclair explains.

“There is a disaster for public health and the development of the mass ownership of cars has moved us away from physical jobs, compared to when Ethel was born,” he stated.

The longevity expert said that social class has always been an unequivocal factor, noting that studies they’ve conducted on people who lived long would mainly be “women of a high social class, married and in the south of England”.

The Centre said that there’s an 18 or 19-year difference in healthy life expectancy between the least and most deprived areas of the country.

This demographic of those living longer is a cause for social concern, as Sinclair worries that the government is not taking it as a call for action.

The blue zones (regions where people live exceptionally long and healthy lives) have a high concentration of centenarians such as Costa Rica, Japan and Greece, Illaria highlighted.

Ilaria stated that they possess characteristics that us Britons do not, such as a greater purpose for life, a good network of friends and family where they’re not having meals alone and are well integrated into life and work.