Madonna thanked her Children for saving her life as she kicked off her Celebration Tour in London on Saturday.

The pop icon was hospitalised with a serious bacterial infection and remained in intensive care for several days earlier this year, forcing her to delay the start of her greatest hits world tour.

As Madonna took to the stage at The O2 on Saturday evening, she confessed to fearing she wouldn’t survive the health crisis.

“I didn’t think I was gonna make it. Neither did my doctors,” she told fans. “I forgot five days of my life — or my death … But my children were there — and my children always save me every time.”

Madonna revealed she was “so happy” to have her children watch the show as she performed an acoustic rendition of I Will Survive.

Some of the star’s kids graced the stage on the first night – Estere, 11, showed off her dance moves during Vogue, and prompted Madonna and her eldest daughter Lourdes, 27, to enthusiastically wave perfect 10 score cards after the routine.

David, 18, strummed on a guitar alongside Madonna for a rendition of Mother and Father, while Mercy James, 17, played piano during Bad Girl.

During the concert Madonna also talked about the Israel-Hamas war and expressed her “heartbreak” for innocent people affected by the conflict.

“It breaks my heart to see children suffering, teenagers suffering, elderly people suffering. All of it is heart breaking,” she said. “But even though our hearts are broken, our spirits cannot be broken … We can unite in a dark and evil way, or we can unite from a place of light and love. And if we all have that in our collective consciousness, we can change the world and we can bring peace — not only to the Middle East, but all over the world.”

Madonna performed a series of her greatest hits during the show, including Ray of Light, Into the Groove, Open Your Heart, Holiday, Like A Prayer, Justify My Love and Vogue.

The Celebration Tour marks the 40th anniversary of her breakout single Holiday.

Madonna is scheduled to perform in countries across Europe including France, Italy, Germany and Sweden, before travelling to North America.