The son of a Canadian diplomat, Jean Vanier embarked upon a naval career that saw him serve during World War Two. But in 1950 he resigned his commission saying that he wanted "to follow Jesus".
He studied theology and philosophy, completing his doctoral studies on happiness in the ethics of Aristotle. He became a teaching professor at St Michael's College in Toronto.
During the Christmas holidays of 1964, he visited a friend who was working as a chaplain for men with learning difficulties just outside Paris. Disturbed by conditions in which 80 men did nothing but walk around in circles, he bought a small house nearby and invited two men from the institution to join him.
L'Arche - the Ark - was born.
Vanier said that living with the disabled helped him to appreciate two truths: first, that people with learning difficulties have a great deal to contribute; second, by living in a community with people - with and without learning disabilities - we open ourselves up to be challenged and to grow.
There are now 147 L'Arche centres in 35 countries, where people with and without disabilities live together as equals. There are a further 1,800 Faith and Light support groups, for people with special needs and their families and friends, across 80 nations.
Jean Vanier's most recent books - A Cry is Heard: My Path to Peace and We Need One Another: Responding to God's Call to Live Together - explore how engaging the weak and the strong in community can lead to fulfilling and productive lives.
In 2015, Vanier became the recipient of the Templeton Prize, an award described as "entirely deserved" by the Archbishop of Canterbury, Justin Welby.
He said Vanier's life had sought to "turn society's assumptions about the strong and the weak upside down. Those the world considers weak, through their disabilities, are those who bring hope and strength lived out in community. Those who are strong discover they need the weak. This is nothing less than the Kingdom of Heaven come to Earth".
In 2017 Vanier was the subject of a documentary, Summer in the Forest, which traced his activism and faith from war time to the present. One of the most moving scenes is toward the end of the film when Vanier officiates at the wedding of two young people who were brought together at L'Arche.
To mark his 90th birthday in 2018, Vanier produced a video containing his Ten Rules for Life to Become More Human. One of them stated: Don't be afraid of not being successful.
Jean Vanier devoted his life to what has been described as the upside down economics of Christianity: that the first shall be last. He embodied a principle first outlined in the New Testament by the Apostle Paul, who said, "When I am weak, then am I strong."