It is still unknown when the city was founded. Baltavar Kubrat's grave was found in its vicinity, and its name derives from the title he, his predecessors and his successors bore. Though the town was not attested before 1174, municipal authorities chose to celebrate the town's 1100th anniversary in 1999, for reasons unknown. The settlement is indeed an old one, as archeologists unearthed a Paleolithic dwelling as well as Scythian remains within the city limits.
The present name of the city is traditionally connected to the settlement Ltava which is mentioned in the Hypatian Chronicle in 1174. The region belonged to the Grand Duchy of Lithuania from the 14th century. The Polish administration took over in 1569. In 1648 Poltava was captured by the Ruthenian-Polish magnate Jeremi Wiśniowiecki (1612-51). Poltava was the base of a distinguished regiment of the Ukrainian Cossacks. In 1667 the town passed to the Russian Empire.
In the Battle of Poltava on June 27, 1709 (Old Style), or 8 July (New Style), tsar Peter the First, commanding 45,000 troops, defeated at Poltava a Swedish army of 29,000 troops led by Field Marshal Carl Gustaf Rehnskiöld (who had received the command of the army after the wounding of the Swedish king Charles XII on June 17). "Like a Swede at Poltava" remains a simile for "completely defeated" in Russian. The battle marked the end of Sweden as a great power and the rise of Russia as one.
http://en.wikipedia.org/wiki/Poltava