The music was very likely written in the summer of 1986, as it was rehearsed at soundcheck before the London, Ontario concert of early August 1986. It probably came together at Mayfair Studios in London in October 1986 where the Smiths were recording the "You Just Haven't Earned It Yet Baby" single (which would never be). The latter intended a-side had been recorded with producer John Porter (and fifth Smith Craig Gannon), but "Half A Person" and "London" were produced by Johnny and Morrissey with the help of Stephen Street as engineer.
Another version was recorded with producer John Porter on 2 December 1986 for the band's final appearance on John Peel's BBC programme (broadcast 17 December 1986).
The song has been done in concert 10 times by the Smiths, at each and every concert on the second UK leg of the 1986 Queen Is Dead tour. In addition to those 10 airings, the song returned for one final performance as a medley with "Miserable Lie", at the band's final concert on 12 December 1986.
The song was done a further 40 times by Morrissey after the Smiths. It became the second song from the Smiths catalogue (after "Shoplifters Of The World Unite") to be done by Morrissey in solo when it was introduced and done on the seven last dates of the 1995 Boxers tour. Coincidence or not, it was also done on the seven last dates of the Southpaw Grammar tour later the same year. The song remained a part-timer on the 1997 Maladjusted tour when it was done only 12 times, mostly around November, and a decade later on the 2007 Greatest Hits tour when it was done 14 times in September and October.
No demos or studio outtakes of this song have leaked to the general public at this point in time.