An Imam and family friend has said that Shaker Aamer's family is "really excited" about being reunited with him and that they have "years of catching up to do".
Sheikh Sulaiman Ghani, Imam of Tooting Islamic Centre, said he remembers Shaker as a man with a "smiling face" and said he was always cheerful.
Sulaiman Ghani has not seen Shaker Aamer in more than 15 years.
Who will mourn Guantanamo Bay? Hardly anyone.
Shaker Aamer spoke to ITV News last week via his lawyer in his final interview before his release from Guantanamo.
Shaker Aamer, the last British detainee at Guantanamo, has been put on a flight back to the UK. Here's what we know about him.