1.Serdica, Sredets, Triaditsa, Sofia
The city changed its names along with its masters. Roman Serdica, or Ulpia Serdica, was called Sredets by the Bulgarians — because, according to the Life of St Nicholas of Sofia, it lies "somewhere in the middle", neither far to the east nor far to the west. The Byzantines called it Triaditsa. The name Sofia comes from the metropolitan church of St Sophia, and in the fourteenth century both names were used side by side: in Ivan Shishman's Vitosha charter the place is "the city of my tsardom, Sofia", while its governor is "the kephale of Sredets".
The Bulgarians settled here for good at the beginning of the ninth century. Sredets had been a prestigious church centre since the council held there in 343, and it is no accident that when the Bulgarian patriarch was stripped of his rank after 971 he sought refuge precisely in Triaditsa. The city was the key to the western lands: in 986 Basil II besieged it in vain and was routed on his retreat in the Trajan's Gate pass, and around 1001 he destroyed part of its fortifications.
2.The City of St John of Rila
The miracles attributed to the relics of the Rila hermit led to their transfer to Sredets. John of Rila became the "lamp of Sredets"; his feast was kept on 19 October — probably the day of the translation — and by 1097 the relics were housed in a church dedicated to him, beside which a monastery soon grew up. The cult spread beyond Bulgaria: between 1166 and 1180 the Byzantine governor of Sredets, George Skylitzes, wrote a new Life of the saint.
The city was not quiet under Byzantine rule either. In 1073 or 1078 the Paulician Leka of Philippopolis, related by marriage to the Pechenegs, appeared in Sredets, stirred up the population and killed Bishop Michael with his own hands.
3.Under the Sceptre of the Asens (1187–1195)
Sredets was among the first prizes in the wars between the restored tsardom and Byzantium. In the late autumn of 1187 Isaac II Angelos reached Triaditsa, but the onset of winter forced him back to his capital to postpone the campaign. After the emperor's rout in the Tryavna pass in 1190 the Bulgarians went on the offensive, pushed into the districts of Sredets and Niš and penetrated deep into the Struma valley; their raids grew especially fierce in 1193–1194.
Around 1194–1195 Tsar Asen imposed his rule firmly on Serdica. At this time he carried the relics of John of Rila, which the Hungarians had recently returned to the city, to the new capital, Tarnovo. From there his troops descended the Struma into eastern Macedonia and near Serres defeated a Byzantine army, capturing its commander Alexios Aspietes.
4.Sredets in the Fourteenth Century
In the centuries that followed Sredets was one of the "populous towns" of the realm and an important stop on the overland routes: Dubrovnik's caravans travelled from Niš to Sofia and on into the country. Foundations of the capital's aristocracy appeared in and around the city. At Boyana a tomb inscription of the voivode Vitomir, son of Tsar Shishko, has been found, and in the cemetery of the church of St Sophia a gold signet ring inscribed "Vitomir's ring". The Sredets Gospels of 1328–1329 mention a Tsar Michael Asen.
Tsar Ivan Alexander founded and adorned the monastery of the Virgin of Vitosha (the Dragalevtsi monastery), and his son Ivan Shishman endowed it with the Vitosha charter. Here the city's administration comes clearly into view for the first time: the kephale of Sredets is expressly warned not to trouble the monastery's property in the city and its surroundings. Ivan Shishman was staying in Sredets in the autumn of 1378 — the Rila charter issued then was probably signed here, after the monks of Rila came to the tsar in the city. Another charter freed from burdens the people of the monastery of St Nicholas at Orehovo who lived in Sredets.
After Ivan Alexander's death in 1371 the city's allegiance has been debated by historians. That same year the Patriarchate of Constantinople entrusted the administration of Triaditsa to the metropolitan of Vidin, and some scholars suppose that Ivan Sratsimir briefly seized Sofia. The Dubrovnik historian Lukarević, however, lists Sofia among Ivan Shishman's lands, and the charter of 1378 confirms that the city then belonged to the tsardom of Tarnovo.
5.The Siege and Fall (1380–1382)
Sredets was a rich and strongly fortified city, and the plain around it was fertile. Turkish raids up the Maritsa valley made it a prime target. Around 1380 the beylerbey of Rumelia, Lala Shahin, besieged the fortress, but the defenders, led by Ban Yanuka, beat off every assault. In his report to the sultan Lala Shahin admits that he led the attacks in person to no avail, and that he was convinced this stout fortress could not be taken quickly without some ruse.
By the Bulgarian chronology the city fell after a long siege in 1382, without Ivan Shishman being able to help it; Donald Nicol gives 1385. One tradition says that Ban Yanuka was captured by a trick while out hunting and that only then did the fortress surrender; an Ottoman account of the city's fall mentions the renegade Uzundzhi Sevindik, who had become Yanuka's falconer. Other legends link Ivan Shishman's name with fighting around Sofia — with Shishman's fort near Samokov and the fortress of Urvich — and tell that his brothers Asen and Michael died there. The reliable sources are silent on these details.
The consequences were felt at once. After the conquest of Sofia the Dragalevtsi monastery lay deserted for more than half a century. The Ottoman chroniclers saw the capture of a city at the crossroads of the whole peninsula as the key to their further campaigns towards Niš and Serbia.