The history of the Czech lands – an area roughly corresponding to the present-day Czech Republic – starts approximately 800,000 years BCE. A simple chopper from that age was discovered at the Red Hill archeological site in Brno. Many different primitive cultures left their traces throughout the Stone Age, which lasted approximately until 2000 BCE. The most widely known culture present in the Czech lands during the pre-historical era is the Únětice Culture, leaving traces for about five centuries from the end of the Stone Age to the start of the Bronze Age. Celts – who came during the 5th century BCE – are the first people known by name. One of the Celtic tribes were the Boii (plural), who gave the Czech lands their first name Boiohaemum – Latin for the Land of Boii. Before the beginning of the Common Era the Celts were mostly pushed out by Germanic tribes. The most notable of those tribes were the Marcomanni and traces of their wars with the Roman Empire were left in south Moravia.

Samo founded the first recorded political union of Slavic tribes, known as Samo's Empire, ruling from 623 until his death in 658. According to Fredegarius, the only contemporary source, Samo was a Frankish merchant who unified several Slavic tribes against robber raids and violence by nearby settled Avars, showing such bravery and command skills in battle that he was elected "King of the Slavs". In 631, Samo successfully defended his realm against the Frankish Kingdom in the three-day Battle of Wogastisburg.