The prehistoric remains in Thrace is not of great number, in comparison to Anatolia. But there is enough to have the oldest inhabited cave at Yarimburgaz in Turkey, which dates back to about 400,000 years ago. The mound at Hocacesme near the ancient town of Ainos has provided some rich findings from Neolithic and Chalcolithic ages. It is well worth to mention number of megaliths (dolmens ) found in Istranca mountains and in the vicinity of the county Lalapasa. Thrace saw a wave of immigration at the end of the 2nd millennium BC and the beginning of the 1st millennium BC. Some of these immigrant peoples moved down to Anatolia and settled there, some settled in Thrace. From the archaeological evidence, it is known that this immigration wave was not of great volume and did not cause much changes in the ethnic structure of Thrace. Thracians of numerous tribes lived side by side and were in constant warfare with each other. Herodotus tells about the war between Apshyntians and Dolonks that was in the 6th C. BCE.
Towards the first half of the 7th C. BCE, Gallipoli peninsula and the northern shores of the Propontis sea was the scene of immigration by Aeolians, Ionians and Megarians. Although they received some resistance from local peoples, they have been able to hold on and build cities such as, Abdera, Byzantium, Sestos, Ainos, Maroenia etc. The southern part of the region formed by Chersoneses (Kallipolis=Gallipoli peninsula) came under control of the Athenians in 555 BCE, and later was invaded and controlled by the Persian King Darius the Great in 513 BCE. In the 6th C BCE, Odrysians under their King Teres and his son Sitalkes have been able to establish a kingdom that stretched from the town Abdera on the Aegean coast in the south to the mouth of river Istros (Danube=Tuna) on the Black Sea coast. Following the death of the king Kotys in 360 BCE., the region got into a turmoil that resulted with the collapse of the Odrysian kingdom. Philip II (359-336 BCE), the king of Macedonia pushed hard to establish his hegemony over Thrace and succeeded to control the interior regions. Philip, beginning from 342 BCE., he started to build colonies in order to keep his control in this area. The well known city of Philipopolis ( Puldudeva=Plovdiv=Filibe) was built in his time. After Philip's death, his son Alexander the Great continued his father's policies, and built the city of Alexandropolis after his name, whose location is unknown. When Alexander began his well known campaign against the Persian Empire in 334 BCE., he trusted the control of Thrace to one of his generals Antipater. While Alexander was in Persia, the Odrysians rebelled under the leadership of their king Seuthes. Seuthes like Alexander and Alexander's successors built a city on his own and named it Seuthopolis. Following the death of Alexander the Great, Thrace changed hands between the Diadochi (Former Generals and Successors to Alexander), and following a series of wars between the generals, Lysimachus was able to secure Thrace for himself. Lysimachus had to make many wars against his rivals for the control of Thrace, and during this time, burned down the city Seuthopolis in 301 BCE. Thrace, in 279 BCE., was invaded by the Galatians who were warrior and plunderer group of people from eastern Europe. Only the wealthy coastal cities withstood their attacks and avoided being invaded by Galatians. Following this chaos, Thrace was shared between many tribes. Philip V (221-179 BCE), the Macedonian king, tried to take advantage of this chaotic status and started a campaign to include this area under his hegemony, but his achievement lived very short and Thrace was able to get rid of the Macedonian hegemony. With the peace treaty of Apameia signed between Antiochus III and the Romans in 188 BCE., Chersoneses (Gallipoli) was left to the Pergamum kingdom whose star began to flare in Western Anatolia. Romans became the only power in the area when the Macedonian kingdom came to the end of its political existence in 168 BCE. Attalus III (138-133 BCE), the last king of Pergamum bequeathed his kingdom to the Romans before his death, and Thracian Chersoneses along with the rest of Pergamum kingdom was taken over by the Romans. Romans showed great interest in this area through which the main route from Europe to Asia passed. During the reign of Augustus, Thrace was formed into a local kingdom under the Sapaei dynasty, and Romans kept this royal dynasty under their control. The first member of the Sapaei kingdom was Kotys, who at the same time ruled the neighbor Korpili tribe. As Rhascuporis his son was not a free man, Kotys was not allowed to use the title of King. But his son Kotys used this title and agreed with the Astians to unite Thrace under his leadership. The Bessian tribe was incorporated in 57 BC. During the reign of Rhoemetalces, the unification of Thrace was completed. The roman historian, Tacitus reports that when Rhoemetalces died, all of Thrace was ruled by himself. But, in 46 BCE, Thracian kingdom came to an abrupt end, all of the region came under the Roman rule as the Province of Thrace. Romans divided Thrace into local administrative units called "Strategia" whose number totaled to 33. Plinius reports the number of Strategia as 50. Most of these Strategia were named after the name of the old Thracian tribes. Only few cities were excluded from the Strategia system and accepted as free cities, those were Abdera, Ainois and Byzantium and Thracian Chersoneses (Dardanelles) in the south enjoyed freedom and exclusion from the Strategia. In the following years, Agrippa gained the control of Thrace, but after his death, the whole region became the imperial property of the Romans under Augustus. The administrative system in Thrace was maintained as organized by Augustus down to the time of Trajan and Hadrian. These two emperors raised the status of the province of Thrace to a higher level and tried to erase the old fashion system of tribal organization. After one and a half century, Diocletian, the emperor (284-305 CE), made changed in the administration of the region and broke the Thracian province into smaller and many units. When Constantine the Great, the emperor of the Eastern Roman Empire known as the Byzantine Empire, moved the capital city from Rome to Byzantium which was renamed to Constantinople after the emperor's name, Thrace continued to develop and flourish as as it was on the main route between east and west.