After living for nearly a hundred years on this planet, I now understand that the most important place on Earth is not on land, but at sea.”"Today, it is in such poor health I would find it hard not to lose hope were it not for the most remarkable discovery of all,

The naturalist has been on our screens for more than seven decades, presenting TV programmes including Planet Earth and Blue Planet.

William praises Attenborough’s dedication as he wishes him happy 99th birthday - Sir David Attenborough has been on our TV screens for more than seven decades presenting programmes such as Planet Earth and The Blue Planet.