An 81-year-old grandmother has become the oldest woman to cycle the length of Britain.

Mavis Paterson pedalled from Land’s End at the southern tip of England to John o’Groats at the top of mainland Scotland, a journey of more than 1,700 kilometres, in memory of her three children.

Known as “Granny Mave,” the pensioner from Dumfries and Galloway in Scotland biked the epic distance over steep terrain and shifting weather in 23 days.

“Some days when we had head winds, rain, wind, I really doubted it,” Paterson told Britain’s ITV News.

“I was struggling on the bike and I hated it.”

Despite the obvious challenge of cycling so far, Paterson faced another hurdle. She has trouble walking and needs two hip replacements.

But she pushed past the pain in memory of her three children, who all died in their 40s within four years of each other.

Her son Sandy died of a heart attack in 2012, daughter Katie after suffering viral pneumonia in 2013 and son Bob in an accident in 2016, according to the BBC.

“When I’m alone at home it just hits me, so the best thing for me is to have a challenge and keep going,” she told CTV News.

Paterson also lost her mother and sister to cancer.

The record-breaking journey has seen her raise more than one hundred thousand dollars for a British charity Macmillan Cancer Support.

“I have three wonderful grandchildren so they are watching and they think granny is a bit mad,” she said.

The grandmother previously cycled across Canada aged 70, according to the BBC.

And last year for her 80th birthday she undertook a 24-hour cycle challenge around Scotland.