Abstract
The article deals with basic characteriristic of external and internal security of first slavic tribes settled in Middle Europe. It describes struggle against external enemies which were Avarian nomadic tribes in the 7th century. It also describes defense against East Francia in the 9th century, importance of fortificated settlements. It characterizes warrior groups as main element of defence. Third part focuses on basic elements of Gret Moravian´s internal security such as law codex named “Law codex for people”