London, January 3: 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."
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.
"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!"
The official F1 Twitter account uploaded a video that included Alonso, Rubens Barrichello and Damon Hill praising Schumacher's career.
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.
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."