when did the first samurai exist in japan

The first recorded samurai emerged during the Heian period in Japan, which lasted from 794 to 1185 AD. However, the concept of warriors serving noble families and fighting for them likely existed before this period. 

During the Heian period, these early samurai were essentially guards or protectors for wealthy landowners and nobility. Over time, their role evolved, and by the end of the Heian period and into the Kamakura period (1185–1333), samurai had become a distinct social class with their own code of ethics, known as bushido, and played a central role in Japanese society and politics.