Although historical records are not completely clear, it is generally agreed that near the beginning of the 5th century B.C.E., democracy first appeared in Athens -- and perhaps this was its first appearance throughout the world. Under the leadership of Cleisthenes, the Athenians overcame yet another dictatorial ruler and then instituted a variety of reforms that placed power in the hands of citizens and otherwise instituted democratic practices throughout Athenian government.
A.D. 1833 or 1833 C.E.
The city state of Athens is considered one of the first (508BC) though there are other possibles for the first including Sumerian, Medes (Iran) and republics of Sanghas & Ganas (India) which also date back to 6th C BC.