The Duchy of Philippopolis was a short-lived duchy of the Latin Empire

Latin Empire

The Latin Empire or Latin Empire of Constantinople is the name given by historians to the feudal Crusader state founded by the leaders of the Fourth Crusade on lands captured from the Byzantine Empire. It was established after the capture of Constantinople in 1204 and lasted until 1261...

 founded after the collapse and partition of the 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...

 in 1204. It included the city of 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...

 and the surrounding region. It was liberated for a short time by Emperor Kaloyan of Bulgaria

Kaloyan of Bulgaria

Kaloyan the Romanslayer , Ivan II , ruled as emperor of Bulgaria 1197-1207. He is the third and youngest brother of Peter IV and Ivan Asen I who managed to restore the Bulgarian Empire...

 in 1207 but was lost by his successor Boril

Boril of Bulgaria

Boril reigned as emperor of Bulgaria from 1207 to 1218. He was the son of an unnamed sister of his predecessor Kaloyan.-Biography:It is unclear whether Boril was party to the murder of Kaloyan in front of the walls of Thessalonica in 1207, but Kaloyan's intended heirs, his nephews Ivan Asen and...

 following his defeat at the Battle of Philippopolis. The territory of the duchy finally joined the Bulgarian Empire

Second Bulgarian Empire

The Second Bulgarian Empire was a medieval Bulgarian state which existed between 1185 and 1396 . A successor of the First Bulgarian Empire, it reached the peak of its power under Kaloyan and Ivan Asen II before gradually being conquered by the Ottomans in the late 14th-early 15th century...

 during the first years of the reign of Ivan Asen II

Ivan Asen II of Bulgaria

-Early rule:He was a son of Ivan Asen I of Bulgaria and Elena . Elena, who survived until after 1235, is sometimes alleged to be a daughter of Stefan Nemanja of Serbia, but this relationship is questionable and would have caused various canonical impediments to marriages between various descendants...

 (1218-1241).

From 1204 to 1205 it was ruled by Renier of Trit

Renier of Trit

Renier of Trit was the first Frankish duke of Philippopolis from 1204 to 1205. He was a knight from Trith-Saint Léger, Hainaut, on the Fourth Crusade....

.