During the time of Abu Bakr (RA) circumstances asked for the collection of various writings to be gathered in one compilation. Following narration gives an account of it;
Narrated Zaid bin Thabit Al-Ansari: Abu Bakr sent for me after the (heavy) casualties among the warriors (of the battle) of Yamama (where a great number of Qurra' were killed). 'Umar was present with Abu Bakr who said, 'Umar has come to me and said, The people have suffered heavy casualties on the day of (the battle of) Yamama, and I am afraid that there will be more casualties among the Qurra' (those who know the Qur'an by heart) at other battle-fields, whereby a large part of the Qur'an may be lost, unless you collect it.