Who was the first collector of the authentic Hadeeths of the Prophet, sallallaahu ‘alayhi wa sallam?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

The process of recording the Hadeeths of the Prophet, sallallaahu ‘alayhi wa sallam, went through several stages, starting from the era of the Companions where some of them wrote what they heard from the Prophet, sallallaahu ‘alayhi wa sallam. So, the Companions were the first people to write down the Hadeeth, but nothing of what they wrote reached us. During the caliphate of ‘Umar ibn Abdul ‘Azeez he wrote for a group of scholars to collect the Hadeeth of the Prophet, sallallaahu ‘alayhi wa sallam, but when they collected the Hadeeths they were mixed with the sayings of the Companions and Fataawa (rulings) of the Taabi‘oon (Followers; generation following the Companions).

The matter remained as such until some scholars suggested collecting the Hadeeth of the Prophet, sallallaahu ‘alayhi wa sallam, in a different manner. Therefore, ‘Ubaydullaah ibn Moosa authored a Musnad, and so did Musaddad Al-Basri, Asad ibn Moosa, and Nu‘aym ibn Hammaad Al-Khuzaa‘i . The methodology of these Musnads was that the Hadeeths of each Companion were grouped separately. Later, scholars of religious sciences followed the methodology of those scholars.

The first one to collect the authentic Hadeeths of the Prophet, sallallaahu ‘alayhi wa sallam, was Imaam Al-Bukhari as stated by scholars of Hadeeth terminology.

Allaah Knows best.