Stefan Nemanja (Serbian Cyrillic: , ; – 13 February 1199) was the Grand Prince (Veliki Župan) of the Serbian Grand Principality (also known as Raška, lat. ) from 1166 to 1196. A member of the Vukanović dynasty, Nemanja founded the Nemanjić dynasty, and is remembered for his contributions to Serbian culture and history, founding what would evolve into the Serbian Empire, as well as the national church. According to the Serbian Academy of Sciences and Arts, Nemanja is also among the most remarkable Serbs for his literary contributions and altruistic attributes.

In 1196, after three decades of warfare and negotiations, including the Third Norman invasion of the Balkans (1185–1186) which consolidated Serbia while distinguishing it from both Western and Byzantine spheres of influence, Nemanja abdicated in favour of his middle son Stefan Nemanjić, who later became the first King of Serbia. Nemanja ultimately went to Mount Athos, where he became a monk and took the name of Simeon, joining his youngest son (later known as Saint Sava), who had already become the first archbishop of the Serbian Orthodox Church.

Together with his son Saint Sava, Nemanja restored the Hilandar Monastery at Mount Athos from 1198 to 1199, and issued the "Charter of Hilandar". The monastery thus became the center of Serbian Orthodox monasticism at Athos. Shortly after his death, the Serbian Orthodox Church canonized Stefan Nemanja, under the name Saint Simeon the Myroblyte ().

Early life Nemanja was born around the year 1113 or 1114 AD in Ribnica, Zeta (in the vicinity of present-day Podgorica, the capital of Montenegro). He was the youngest son of Zavida, a Prince of Zachlumia, who after a conflict with his brothers was sent to Ribnica where he had the title of Lord. Zavida (Beli Uroš) was most probably a son of Uroš I or Vukan. Since western Zeta was under Roman Catholic jurisdiction, Nemanja received a Latin baptism, although much of his later life was spent balancing Western and Eastern forms of Christianity.

Byzantine-Hungarian War

In 1163, Emperor Manuel I Comnenus came to Niš with the army via Serdica (Sofia), where, according to John Kinnamos, he decided "to deal with things concerning Serbia". At that time, Serbia was ruled by the Grand Župan Desa, an ally of Stephen III in the Hungarian dynastic conflicts, and thus an opponent of Manuel. When in 1165 Desa was finally forced to come to Niš before the emperor, his connections with the Hungarian king Stephen III were revealed, Desa called him his master, Manuel I decided to take him to court and punish him. Desa was first detained and kept under guard, and then sent to the court prison in Constantinople.

The land was given by the emperor to the administration of Zavida's sons, who were in the pro-Byzantine party: Tihomir, Stracimir, Miroslav and the youngest Nemanja. Tihomir was the oldest and became the Grand Župan of Serbia. In January 1166, Tihomir was recognized by the brothers who were given to rule other certain parts of Serbia and the Serbian-Byzantine frontier. Stracimir held the areas around West Morava, Miroslav Zahumlje, while Stefan Nemanja was given the areas around Ibar, and Dubočica (around Leskovac), which probably was historical region of Dendra west of Niš.

The Byzantine emperor Manuel I Comnenus launched a large army against Hungary because he was informed of their dissatisfaction and internal conflicts. The Hungarian prince Béla III had to live in Constantinople, where he was married, and Béla's lands, Dalmatia with southern Hungary (below Velebit), had to come under Constantinople's rule. There is resistance in Hungary, which is why Emperor Manuel embarks on a campaign. The Byzantine army conquered Zemun and Srem in 1165. The Byzantines were accompanied by the obligatory detachments of Serbs. The second Byzantine army under command of John Doukas Komnenos moved west, across Serbia and Bosnia towards the Adriatic coast. Without significant resistance, they took all the cities from Split to Bar, forcing them to recognize Byzantine rule.

The Byzantines also had success in a campaign in Italy where they captured an important seaport on the west coast of the Adriatic, Ancona. Venice, which had previously turned to Byzantium for help during the conquest of Friedrich Barbarossa in northern Italy, changed its attitude towards the Byzantines for fear of losing the Adriatic. It approached Hungary as a natural ally against the Byzantines. At the same time, they began to work among the Serbs, especially in Serbia, in order to rebel against Byzantium.

In 1166, the Hungarians counterattacked to push Byzantium out of the newly conquered areas. However, in response, Emperor Manuel launched three armies against Hungary, one from the Danube, and the other two across the Carpathians, towards the center of Pannonia. While the main Hungarian army was operating towards the Danube, Belgrade and Braničevo, two Byzantine armies went deep into their territory, causing general panic. The Hungarians were forced to seek peace through intermediaries to their detriment in 1167.

As the ideal candidate of Venice and Hungary among the Serbs appeared Nemanja, when his brothers and, above all, Tihomir imprisoned him in a cave near Fortress Ras. Nemanja probably hoped that he would take the place of Desa, as the former representative of the pro-Greek party, while Emperor Manuel brought his eldest brother Tihomir to the throne. Angry because of that, Nemanja changes his policy in favor of Hungary and its allies. Nemanja escaped from the dungeon, it is not known with whose help. Nemanja's son and biographer, Stefan Nemanjić, describing his father's life, says how he escaped with the help of "heavenly forces": "And this again, because of meekness and justice, and wonderful humility, and because of all good customs, with a high arm he brought him out of the rocky cave, and brought him to the throne of his fatherland, and raised him up as the great lord of all the world."

Rise to the throne (1168–1172) In 1166 or 1167, Nemanja first expanded his territories and conquered Kotor, and then gathered his supporters in Ras and started a conflict against Tihomir, who was looking for support from the Byzantines. Nemanja overthrew Tihomir, provoking Byzantines action in autumn 1168:

At that time, William of Tyre, an emissary of Amalric, a Latin King of Jerusalem, arrived at the diplomatic mission in Constantinople. His goal was for Byzantium to join the crusade against Egypt. During his stay in Constantinople, probably under the influence of the Byzantines, William of Tyre left negative classifications about Serbs in his reports.

The following year, Nemanja attacked the Byzantine vassal, Prince of Zeta Radoslav, and on that occasion annexed to his country a part of the then Zeta and the Neretva region. Soon, Manuel I Komnenos came into conflict with the Venetian Republic, and on his order, on 12 March 1171, all Venetian property in Byzantium was confiscated. In response to this, from Venecia was launched Venetian navy with about 120 ships to Byzantine possessions. The Venetian fleet headed east in September of that year, conquering, by the way, Byzantine Trogir and Dubrovnik. Then Nemanja entered into closer ties with the Venetians and began attacks on Byzantine Kotor, simultaneously carrying out raids through the Moravian valley through which the main public road passes between Byzantine Belgrade and Niš. According to Arnold of Lübeck on that road, near fortress Ravno, in March 1172, the Serbs carried out a night attack on the camp of Western knights and pilgrims led by Henry the Lion accompanied by the Byzantines. Arnold of Lübeck also left a very negative opinion in his chronicle about Serbs. Probably under the impression of the night attack, he even called them the "sons of Belial." Meanwhile, in 1171, Saladin was appointed sultan of Egypt, who would become one of the greatest defenders of Islam in history.

The Kingdom of Hungary also wanted to join the fight against Byzantium, and the Holy Roman Empire of Frederick Barbarossa (1152–1190), also supported this alliance. Nemanja expected Hungarian help, but in the meantime, king Stephen III of Hungary died on 4 March 1172. The Hungarian emissaries went to Serdica (Sofia), where Emperor Manuel encamped with the army, preparing for the campaign. The Hungarian throne was won by Manuel's candidate Bela III (1173–1196). In the meantime, during the winter of 1171/72 on the island of Chios, the Venetian army was decimated by an epidemic, so that the Serbs were left alone in the fight against Byzantium. Manuel immediately took advantage of the favorable moment and after receiving the Hungarian emissaries, he headed for the Serbs at the head of the army. Before the oncoming Byzantine army, the grand zoupan Nemanja retreated to the mountains. According to the Byzantine historian John Kinnamos, the Venetians incited Nemanja to revolt.

Byzantine vassal (1172–1182)

This conflict ended with Nemanja's surrender to Emperor Manuel. One day, Nemanja ritually obeyed Manuel I Komnenus in Niš. Barefoot, with his clothes torn to the elbows, a rope around his neck and a sword in his hands, he entered the Byzantine camp and went out to the emperor. Arriving in front of Manuel, he fell on his knees in front of him, handing him his sword, to do with him what he wanted. The Byzantine emperor accepted his humility, agreeing to the renewal of vassal obligations and leaving Nemanja in the position of grand zoupan. The final part of this episode took place in Constantinople, where Nemanja was taken as a slave in Manoel's triumphal procession, while the gathered people ridiculed him. He was even shown a "series of wall paintings that the emperor had commissioned to commemorate his victories over the Serbs; his alleged reaction is recorded in an oration by Eustathius of Thessalonica: 'Seeing these paintings, he agrees with everything and approves of the visual feast. In one respect only does he chide the painter, namely that the latter has not called him a slave (doulos) in all the scenes of the triumph'."

The Byzantine emperor Manuel Comnenus returned Nemanja to the position of Grand Župan, and he confirmed to his brothers their areas – Stracimir around the West Moravia and Miroslav Zachlumia. Upon his return to Serbia, Nemanja turned to consolidating the central government, and forced Tihomir's son and successor Prvoslav to renounce the ruler's claims in his favor.

In accordance with his vassal duties, Nemanja regularly sent auxiliary detachments to Byzantine military campaigns. Serbian detachments were also part of the Byzantine army that was defeated by the troops of the Sultanate of Rum in the battle of Myriokephalon on 17 September 1176 in the gorges of Asia Minor.

Bogumilism reached its peak in the Byzantine Empire during the 11th and in the first half of the 12th century. At the end of the 12th century, among Serbs and other Balkan Slavs, there was a very widespread 'Slavic' Gnosticism or dualistic teaching called Bogumilism. The main political tendency of Bogomilism was resistance to the Byzantine state and church authorities.