North Thrace or Northern Thrace (as opposed to Western Thrace

Western Thrace

Western Thrace or simply Thrace is a geographic and historical region of Greece, located between the Nestos and Evros rivers in the northeast of the country. Together with the regions of Macedonia and Epirus, it is often referred to informally as northern Greece...

 and Eastern Thrace to the south) constitutes the northern and the largest part of the historical region of Thrace

Thrace

Thrace is a historical and geographic area in southeast Europe. As a geographical concept, Thrace designates a region bounded by the Balkan Mountains on the north, Rhodope Mountains and the Aegean Sea on the south, and by the Black Sea and the Sea of Marmara on the east...

. Bulgarian Thrace is located in Southern Bulgaria

Southern Bulgaria

Southern Bulgaria is the southern half of the territory of Bulgaria, located to the south of the main ridge of the Balkan Mountains which conventionally separates the country into a northern and a southern part...

 and refers to the whole territory south of the Balkan

Balkan Mountains

The Balkan mountain range is a mountain range in the eastern part of the Balkan Peninsula. The Balkan range runs 560 km from the Vrashka Chuka Peak on the border between Bulgaria and eastern Serbia eastward through central Bulgaria to Cape Emine on the Black Sea...

 and east of the Mesta River

Mesta River

The Nestos or Mesta , formerly the Mesta Karasu , is a river in Bulgaria and Greece. It rises in the Rila Mountains and flows into the Aegean Sea near the island of Thasos. It plunges down towering canyons toward the Aegean Sea through mostly metamorphic formations...

; to the Greek and Turkish borders in south and to the Black Sea

Black Sea

The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

 in east. It encompasses Sredna Gora

Sredna Gora

Sredna Gora is a mountain range in central Bulgaria, situated south of and parallel to Balkan mountain range and extending from the river Iskar to the west and the elbow of Tundzha north of Yambol to the east. Sredna Gora is 285 km long, reaching 50 km at its greatest width...

, the Upper Thracian Plain

Upper Thracian Plain

The Upper Thracian Plain constitutes the northern part of the historical region of Thrace. It is located in southern Bulgaria, between the Sredna Gora mountains to the north and west; the Rhodopes, Sakar and Strandzha to the south; and the Black Sea to the east. A fertile agricultural region, the...

 and 90% of the Rhodopes. The climate divers from continental to transitional continental and mountainous. The highest temperature recorded in Bulgaria occurred here: it was 45.2 °C

Celsius

Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...

 at Sadovo

Sadovo

Sadovo is a small town in the Plovdiv Province, central Bulgaria. The population is 2 551. Most of the people are employed in agriculture, which due to the fertile soils and the high levels of mechanisation is efficient and highly productive. Major crops are apples, tomatoes, peppers, wheat,...

 in 1916. Important rivers are the Maritsa

Maritsa

The Maritsa or Evros , ) is, with a length of 480 km, the longest river that runs solely in the interior of the Balkans. It has its origin in the Rila Mountains in Western Bulgaria, flowing southeast between the Balkan and Rhodope Mountains, past Plovdiv and Parvomay to Edirne, Turkey...

 and its tributaries. Important cities include Plovdiv

Plovdiv

Plovdiv is the second-largest city in Bulgaria after Sofia with a population of 338,153 inhabitants according to Census 2011. Plovdiv's history spans some 6,000 years, with traces of a Neolithic settlement dating to roughly 4000 BC; it is one of the oldest cities in Europe...

, Burgas

Burgas

-History:During the rule of the Ancient Romans, near Burgas, Debeltum was established as a military colony for veterans by Vespasian. In the Middle Ages, a small fortress called Pyrgos was erected where Burgas is today and was most probably used as a watchtower...

, Stara Zagora

Stara Zagora

Stara Zagora is the sixth largest city in Bulgaria, and a nationally important economic center. Located in Southern Bulgaria, it is the administrative capital of the homonymous Stara Zagora Province...

, Sliven

Sliven

Sliven is the eighth-largest city in Bulgaria and the administrative and industrial centre of Sliven Province and municipality. It is a relatively large town with 89,848 inhabitants, as of February 2011....

, Haskovo

Haskovo

Haskovo , is a city, an administrative centre of the homonymous Haskovo Province in southern Bulgaria, not far from the borders with Greece and Turkey. As of February 2011, it has a population of 74,843 inhabitants....

, Yambol

Yambol

Yambol is a city in southeastern Bulgaria, an administrative centre of Yambol Province. It lies on both banks of the Tundzha river in the historical region of Thrace. As of February 2011, the town has a population of 72,843 inhabitants. It is occasionally spelt 'Jambol'.The administrative centres...

, Pazardzhik

Pazardzhik

Pazardzhik is a city situated along the banks of the Maritsa river, Southern Bulgaria. It is the capital of Pazardzhik Province and centre for the homonymous Pazardzhik Municipality...

, Asenovgrad

Asenovgrad

Asenovgrad is a town in central southern Bulgaria, part of Plovdiv Province.-History:Asenovgrad was founded by the Thracians as Stenímachos around 300–400 BC. In 72 BC the city was captured by the troops of the Roman Empire as part of the Roman expansion towards the Black Sea. After a long period...

, Kardzhali

Kardzhali

Kardzhali or Kurdzhali is a town in Bulgaria, capital of Kardzhali Province in the Eastern Rhodopes. Near the town is the noted Kardzhali Dam.-Geography:...

, Dimitrovgrad

Dimitrovgrad

Dimitrovgrad is the name of three towns in Europe:* Dimitrovgrad, Bulgaria* Dimitrovgrad, Russia* Dimitrovgrad, SerbiaAll three were named after Georgi Dimitrov....

, Kazanlak

Kazanlak

Kazanlak, formerly Kazanlık is a Bulgarian town in Stara Zagora Province, located in the middle of the plain of the same name, at the foot of the Balkan mountain range, at the eastern end of the Rose Valley...

 and Smolyan

Smolyan

Smolyan is a town and ski resort in the very south of Bulgaria not far from the border with Greece. It is the administrative and industrial centre of the homonymous Smolyan Province...

.

The lands of the nowadays region were part of the Bulgarian

Bulgarian Empire

Bulgarian Empire is a term used to describe two periods in the medieval history of Bulgaria, during which it acted as a key regional power in Europe in general and in Southeastern Europe in particular, rivalling Byzantium...

 and Byzantine Empire

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 before the gradual Ottoman occupation in the 1300s. The Ottoman Turks created the autonomous province of Eastern Rumelia

Eastern Rumelia

Eastern Rumelia or Eastern Roumelia was an administratively autonomous province in the Ottoman Empire and Principality of Bulgaria from 1878 to 1908. It was under full Bulgarian control from 1885 on, when it willingly united with the tributary Principality of Bulgaria after a bloodless revolution...

in northern Thrace in 1878. The region was annexed to the Bulgarian kingdom in 1885.