From his 2011 Q & A with the Guardian:
How did you come to write Bernard Shaw?--Marshal Zeringue
I was asked to write Shaw's biography by his three copyright holders: the British Museum, the National Gallery of Ireland and the Royal Academy of Dramatic Art, following the publication of my Life of Lytton Strachey. I was terrified by the immensity of the task and pleaded that I had already begun another biography – a Life of the Welsh artist Augustus John. But the Shaw estate was not so easily put off and a few years later I found myself travelling to Ireland to begin my research into GBS.
What was most difficult about it?
"All length is torture", Antony says after hearing of Cleopatra's death. I remember these words coming into my head as I worked on Shaw. He lived into his mid-90s and, with his shorthand and his secretaries, could write (it seemed to me) more words in a day than I could read in a day. At the end of one letter the best part of 50 pages long, he apologised: "Forgive this long letter. I didn't have time to write a short one." What was I to do with...[read on]