Captain Sir Tom Moore’s legacy will live on “for years and years”, charities have vowed, as his death prompted heartfelt tributes from around the world.

The charity fundraiser, who raised more than £32 million for the NHS during the first lockdown, died at the age of 100 on Tuesday morning after testing positive for Covid-19.

His family said the last year of his life was “nothing short of remarkable”, and that he had “experienced things he’d only ever dreamed of”.

Sir Tom set out to raise £1,000 for NHS Charities Together by walking 100 laps of his garden before his 100th birthday last April – but his efforts struck a chord with the nation and the donations flooded in.

In acknowledgement of his efforts, he was knighted by the Queen during a unique open-air ceremony at Windsor Castle in summer 2020.

Ellie Orton, chief executive of NHS Charities Together, said Sir Tom “lifted the spirits of an entire nation” and demonstrated that “you’re never too old, you’re never too anything to care for people and to make a difference”.

She told the PA news agency: “He really was a beacon of hope, the optimism that he brought in and hope to us in a really dark and difficult time for this nation and particularly for the NHS is just incredible.

“He is held in such amazing high regard, he is a national hero and his legacy will live on in the NHS for years and years to come.”

The Captain Tom Foundation, which was set up to support causes close to Sir Tom’s heart, said its work would “aspire to ensure Tom’s message of hope becomes an enduring legacy”.

“Whilst we mourn his loss, we celebrate his life and will be forever grateful for his optimistic philosophy and wonderful spirit,” a statement said.

“Thank you Captain Sir Tom. Because of you tomorrow will be a good day for so many more.”

Sir Tom had been taken to hospital on Sunday after being treated for pneumonia for some time and testing positive for coronavirus last week.

His family praised the care he had received from the NHS and said they had been able to spend time with him in his final hours.

In a statement, his daughters Hannah Ingram-Moore and Lucy Teixeira said: “We are so grateful that we were with him during the last hours of his life; Hannah, Benjie and Georgia by his bedside and Lucy on FaceTime.

“We spent hours chatting to him, reminiscing about our childhood and our wonderful mother. We shared laughter and tears together.”

They added: “Whilst he’d been in so many hearts for just a short time, he was an incredible father and grandfather, and he will stay alive in our hearts forever.”

Prime Minister Boris Johnson described the veteran as “not just a national inspiration but a beacon of hope for the world”.

“In the face of this country’s deepest post-war crisis, he united us all, he cheered us all up, and he embodied the triumph of the human spirit,” he said.

Buckingham Palace said the Queen would be sending a private message of condolence to Sir Tom’s family, adding: “Her thoughts, and those of the royal family, are with them, recognising the inspiration he provided for the whole nation and others across the world.”

The White House also joined the chorus of tributes, saying the US joined the UK “in honouring the memory of Captain Sir Tom Moore, who inspired millions through his life and his actions”.

Singer Michael Ball, who recorded a charity single with Sir Tom that reached number one, said he had spoken to Sir Tom’s family and they had told him the veteran “was so proud and so content and he didn’t suffer”.

While presenting The One Show on the BBC on Tuesday night, Ball said: “What keeps them going, I think, is the outpouring of love and respect for everything that Tom achieved over the last year. It has been extraordinary.”

Veteran fundraiser Lloyd Scott, famous for completing endurance challenges in a deep sea diving suit, said Sir Tom had brought out “the very best of humanity”.

Mr Scott, who has raised £5 million for charity over the past 30 years and met Sir Tom, told PA: “Although the amount of money he raised was absolutely mind-boggling, I think that his legacy was really how he touched the souls of everybody – not just in this country but around the world.”

Sir Tom’s fundraising efforts went on to inspire others to take on similar charity challenges, including Dabirul Islam Choudhury, who raised more than £420,000 by walking 970 laps of his communal garden while fasting during the Islamic holy month of Ramadan.

Mr Choudhury said: “He is our real hero and we will miss him terribly.”

The flag above 10 Downing Street was flown at half-mast on Tuesday evening, while landmarks including the London Eye, Wembley Stadium and Blackpool Tower were lit up and a tribute was broadcast on the billboard lights at Piccadilly Circus.

Floral tributes were laid at the gate to his family home in the village of Marston Moretaine in Bedfordshire, as neighbours described him as “a legend, inspiring, a hero”.