At 8am, he slid into the room unescorted, unobserved, his pace so gentle as if not to hurt the wooden floor of a café opposite Richmond bus station in southwest London. His black leather bag hung on his right shoulder.

Once seated, he ordered his breakfast – scrambled eggs, mushrooms, tea, and water.

Bald, grey-haired Tom Ilube, 53, tops a list of the UK’s 100 most influential black citizens of African and Caribbean origin. He comes well before Mo Farah, the Olympic long-distance runner, and Lewis Hamilton, the Formula 1 driver.

The competition is stiff as of the UK’s 63 million people, there are 1.9 million British of African and Caribbean descent, according to a 2011 census.

"It was definitely a surprise. I am basically an introvert geek, so I just go about doing my things. And actually my wife said, ‘I am not sure you are even the most influential person in our house,’” he said with a laugh on BBC Focus on Africa.

"I was honoured to be selected. I’m realistic about what it meant,” he said as he chewed his breakfast in Richmond. "The panel meant to shine a spotlight on a black person like me outside sports or entertainment in order to show black people, black girls and boys, to show society that you can be important in other fields other than those fields most people associate with black people.”

A philanthropist, cyber security expert, and a pro-girls education activist, Ilube was born to a Nigerian BBC television engineer and an English woman. He grew up in the UK until he was seven years old and moved with his family to Kampala, Uganda, returned to the UK years later for high school, and then headed to Nigeria.

He would return to the UK in 1984 with a bachelor’s degree in physics from Nigeria’s Benin University. On loans, he later headed to City, University of London, earning a Master’s in Business Administration.

In 2011, Ilube founded the UK’s Hammersmith Academy, a state secondary school reported to be one of the most innovative technology schools in the country.

Ilube may look and sound quite self-effacing, but deep inside he is quite tenacious, rebellious even – a never-give-up kind of person. His wife rejected him on his first proposal in 1992. And well over 100 of his job applications were turned down. In the end, he succeeded in both.

"A lot of drive, the ability to fail and bounce back. That’s my key aspect,” he said.

"When I get a rejection, I smile to myself because I think, ‘You think you can reject me but you’re not going to stop me [from going] where I want to be.’ Rejections are inspirations for me,” he said.

His first job offer would come in 1984, as a computer technologist at British Airways.

Time was ticking away. It had been almost an hour – and the model-looking waitress was by now clearing the wooden table. Ilube still sipped on his glass of water.

In his philanthropy work, he decided to focus on education instead of jumping from idea to idea.

"My mom was a teacher and she had a huge influence in my life. Science is my passion, so I focused on technology. That’s where I thought I could make a difference,” Ilube said.

"Young women were not studying science and technology [but it’s not that] they were not up to. They are not encouraged,” he said. "And if you asked people [what] an engineer looks like, they would describe a man before they describe a woman. So the whole environment is against girls and women.”

And so, since August, he has run African Gifted Foundation, a nonprofit that provides quality education at the African Science Academy, a girls-only high school in Accra, Ghana. It will begin admitting some Rwandan schoolgirls next year. A senior official at the Rwanda High Commission in the UK confirmed the development.

"I am trying to address that by creating an environment that is just designed for African young girls and women [to pursue] a future in science, engineering, and mathematics,” said Ilube. "It’s going well, but it is still early days.”

Emmanuella Adamah, 18, is lucky to be among the 24-student first intake at the school. From a subsistence farming family in eastern Ghana, she, like 23 other young girls from Ghana, Nigeria, Cameroon, Sierra Leone, Ethiopia, and Uganda, benefits from a full tuition scholarship at the one-year, pre-university institution. They all take three subjects at A level — physics, pure math, and further math — and receive lectures from foreign guest speakers.

"It’s quite interesting. It’s more challenging and more daring,” Adamah said of the course, through a Skype video link from Accra. "I really love to play with computers.”

Chatting to Adamah, it became clear the kind of thinking she exhibits goes beyond a usual teenager’s. She thinks big and in context. She plans to study electrical engineering to help solve her country’s energy crisis. Less than a half of Ghana’s 25.5 million people have access to electricity.

"We don’t get constant power supply. Why is that?” she asked.

Adamah sounded committed to achieving her dream. But it is a dream she knows very well would nearly be impossible without Tom Ilube’s school.

"Wow! How could I think of him? This man, I would love to say to him that he is my mentor. He inspires me,” she said of Ilube as she fought back tears of gratitude.

According to Rhianna, Ilube’s 22-year-old daughter who is based at the school in Accra, her dad and a small fundraising team raise money from private donors and philanthropists.

"This year, they raised enough money for every student to be here on a full scholarship,” she said. "Next year, we aim for around 25 per cent of students to be fee paying.”

"The aim is not necessarily to send all of them abroad. It is more to equip them with very high academic skills and inspiration to prepare them well for uni [university] and beyond,” said Rhianna.

So the school that started four years earlier as a two-week summer school at Uganda’s Makerere University has turned into a continental, girls-only science and technology high school.

"It was too short. Students got engaged, but had to go back to their schools and couldn’t progress because their schools were not focused on science,” said Ilube.

There was then a need to keep the students together for a long time. And Ghana stood out.

"I wanted a world-class institution, with outside speakers, in a different part of Africa. And Ghana is well-organised, easy to operate in, values education, and a peaceful country, and parents are quite positive to send their children there,” he said.

But the school is more than an academic institution. It is a metaphor for what Ilube plans to achieve for the whole of Africa. A continent, he said, that wields so much power with its 1.2 billion people and immense size — it’s so big that India, China, Europe, and North America can all fit in it. Yet, he said, a "pre-colonial” mindset has held the continent back.

"We are very fragmented in our minds,” he said. African countries "don’t really work together. The world doesn’t really feel the impact of what would be the world’s most powerful continent.”

And that is where his school idea fits in.

"So the [the few people] working with each other as engineers from different countries can bring about pan-Africanism,” he said.

And making a difference to the world – however little that could be – is what haunts him, even keeps him awake at night.

"Am I really making a difference to the world I live in?” he asks himself sometimes. "And a difference, it doesn’t mean always a big thing,” he said.

"There is an area of science about chaos, where a small change here can make a big change there. A butterfly flutters its wings in Brazil and it can cause a tornado in Tokyo – a ripple effect over there,” he said poetically, now deep into scientific reasoning.

"In a sense, [I hope] to create ripples that can cause an impact, though I might not live to see the impact I suppose. So what keeps me awake at night is, am I creating ripples that might cause an effect in the future?” he asked, rhetorically.

The morning clouds had begun clearing over the café in Richmond. And outside the glass windows of the café, people were rushing to work, buses zipping back and forth. Ilube would soon be no exception. He’d emptied his glass of water by now.

The man who enjoys reading Ian Rankin’s fiction and graphic novels, going to the cinema, playing rugby – his son, Matthew, 18, plays it too – and walking in Richmond’s park in his spare time, left the café and looked left and right as he crossed the road to his workplace nearby.

He grew smaller in the distance and then disappeared in the crowd. Nobody seemed to notice this new figure on a UK celebrity list. And Ilube likes it that way – keeping a low profile.

The writer is a Rwandan freelance journalist. A Chevening Scholar, he is currently pursuing an MA Investigative Journalism Programme at City, University of London.