Michael Schumacher received tributes from across the world of Formula One on his 50th birthday on Thursday.
The legendary seven-time F1 world champion has not been seen in public since suffering serious head injuries in a skiing accident in December 2013.
His family issued a statement on Wednesday stating he is "in the very best of hands" and they are "doing everything humanly possible to help him".
Ferrari, with whom Schumacher won five drivers' titles in a row, marked the German's birthday by opening a special exhibition in his honour at their headquarters in Maranello.
The team also tweeted: "Our champ turns 50 today. We're all with you Michael."
Our champ turns 50 today. We’re all with you Michael #KeepFighting pic.twitter.com/hN4n8Br1ap
— Scuderia Ferrari (@ScuderiaFerrari) January 3, 2019
Following four seasons in retirement after finishing second to Fernando Alonso in the drivers' standings in 2006, Schumacher returned to the sport with Mercedes.
He spent three years with the team and Mercedes chief Toto Wolff emphasised the role he has played in the manufacturer winning every title on offer since 2014.
"Michael is one of the founding fathers of the success we have had in the last five years," said Wolff.
50 years ago, a star was born. A star who shaped and changed @F1 forever. Who broke records, redefined excellence and helped lay the foundations for our future success.
— Mercedes-AMG F1 (@MercedesAMGF1) January 3, 2019
We’d like to send our very best wishes to Michael @Schumacher on his 50th birthday. #KeepFighting #Michael50 pic.twitter.com/247WKprWCD
"There is no other driver like him and his vast experience contributed tremendously in the development of our team.
"He played a crucial role when we re-joined F1 and was one of the people who laid the foundation for our future success. We're extremely grateful for everything he did for us.
"Today, we all tip our hats to you - happy birthday, Michael!"
Lewis Hamilton replaced Schumacher at Mercedes in 2013 and the five-time champion cited the German as a "true inspiration".
"Wishing you a happy birthday, Michael. 50 years of life and a legacy that will last forever," Hamilton wrote on Instagram.
"What an honour it is to say that I have raced with you. You've always been a true inspiration to me and the entire world. Keep fighting, Champ."
The official F1 Twitter account uploaded a video that included Alonso, Rubens Barrichello and Damon Hill praising Schumacher's career.
91 victories, seven world titles, and just one word to describe him...
— Formula 1 (@F1) January 3, 2019
Some of those that know Michael @schumacher best sum up the legend in just a single word. What word would you use?#KeepFightingMichael #Michael50 pic.twitter.com/pkAjK5nGIR
A separate tweet read: "We join the whole of the F1 family in sending Michael Schumacher our very best wishes on his 50th birthday."
Renault, Williams and McLaren were among the other teams from the paddock to publish messages of support on social media.
Happy birthday champ. Wishing you the very best on your 50th. #KeepFightingMichael #Michael50 pic.twitter.com/7J4c4OZLm9
— Renault Sport F1 (@RenaultSportF1) January 3, 2019
Wishing a Happy 50th Birthday to the one and only Michael Schumacher.#KeepFightingMichael pic.twitter.com/uPX0iJDcKe
— WILLIAMS RACING (@WilliamsRacing) January 3, 2019
All of us at McLaren are sending our best wishes to Michael @Schumacher and his friends and family as he celebrates his 50th birthday today. #KeepFightingMichael #Michael50 pic.twitter.com/K47xMQy1A3
— McLaren (@McLarenF1) January 3, 2019
FIA president Jean Todt posted on Twitter: "For his 50th birthday, affectionate thoughts for Michael Schumacher, the greatest F1 champion in history, with unbroken records.
"Michael, you've always been a fighter and you always will be."
For his 50th birthday, affectionate thoughts for Michael @schumacher , the greatest @F1 champion in history, with unbroken records.
— Jean Todt (@JeanTodt) January 3, 2019
Michael, you’ve always been a fighter and you always will be.#Michael50 #TeamMichael #KeepFighting #F1 pic.twitter.com/S9PDNF7s2Q