Mick Fleetwood paid tribute to Kirwan in a post on the band's Facebook: “Danny was a huge force in our early years. Danny’s true legacy, in my mind, will forever live on in the music he wrote and played so beautifully as a part of the foundation of Fleetwood Mac, that has now endured for over 50 years. Thank you, Danny Kirwan. You will forever be missed!”

Joining the band at the age of 18, Kirwan was with the band throughout their blues-rock era. He became the band’s third guitarist alongside Peter Green and Jeremy Spencer, and performed on five of their albums from 1968 to 1972.

This became a period of upheaval for the band. Green left in 1970, followed in 1971 by Spencer, who joined the Children of God cult, while Christine McVie joined the band in 1969.

During his time with the band, Kirwan developed an alcohol problem, and was eventually fired from the band in 1972. This ushered in an even more unstable period before the arrival of Stevie Nicks and Lindsey Buckingham, which led to Fleetwood Mac's period of greatest success, with Rumours being released in 1977.

After leaving the band, Kirwan went solo and released four albums throughout the 70s, featuring his own songs, as well as idiosyncratic covers such as a reggae take on the Beatles’ 'Let It Be'.

Shortly after this, Kirwan became homeless. Then in 1993 Fleetwood used the Missing Persons Bureau to trace him. Kirwan said he had been living a hermitic existence in a Brixton basement flat for years, followed by four years at a St Mungo’s shelter in central London, living off social security and small royalty payments. Speaking to the Independent at the time, Kirwan said: “I’ve been through a bit of a rough patch but I’m not too bad. I get by and I suppose I am homeless, but then I’ve never really had a home since our early days on tour. I couldn’t handle it all mentally and I had to get out. I can’t settle.”

The guitarist was 68 when he died.