Who collected the Quran in the form of book?

After the Battle of Yamama (633 CE), many Huffaz (Qur'an memorizers) were martyred. Fearing the loss of Qur’anic knowledge, Hazrat Umar (RA) advised Caliph Hazrat Abu Bakr (RA) to compile the Qur’an in written form. He assigned this task to Zaid ibn Thabit (RA), who carefully gathered all verses from written sources and verified them with living memorizers. This was the first official compilation of the Qur’an into a physical manuscript (Mushaf). Later, during Hazrat Uthman’s (RA) caliphate, copies were standardized and distributed — but the initial collection into a book was under Hazrat Abu Bakr (RA).