Izborsk contains one of the most ancient and impressive fortresses of Western Russia. According to the Russian Primary Chronicle, the town was the seat of Rurik's brother Truvor from 862-864. Although his burial mound is still shown to occasional tourists, archaeological excavations of long barrows abounding in the vicinity did not reveal the presence of the Varangian settlement at the site, indicating that Izborsk was an important centre of the early Krivichs.
The next mention of the town in Slavonic chronicles dates back to 1233, when the place was captured by the Livonian Brothers of the Sword. Pskov moved the fortress to a more convenient site in 1302. The most ancient extant structure is the Tower Lukovka (literally, "Onion Tower"), constructed in 1330. At that time it was the only stone building west of Pskov and adjoined a wooden wall. After seven other stone towers and the new stone wall were completed, Lukovka became a watch-tower. The Nativity church within the fortress was built in the 16th century. Near the fortress is a museum of stone crosses.
In the later 1500s Izborsk was one of the smaller, but nonetheless strategically important fortresses that protected the northwest Russian borders from invasion. The fortress was supposed to be impregnable, which is why the seizure of it in 1569 by a small Lithuanian regiment came as such a shock to the then ruler, Ivan the Terrible. The relative ease and suspicious circumstances of the seizure of the fortress deeply troubled the already paranoid Ivan. In the dead of night Teterin, a Russian turncoat disguised as an oprichnik, ordered the gates of the town be opened in the name of the oprichnina, thus allowing the enemy regiment to enter and overtake the fortress.
Though Ivan managed to retake the city with little difficulty, the treachery and conspiracy involved in the original seizure led him to order the executions of the assistant crown secretaries of Izborsk, as well as the secretaries of the surrounding fortresses. With rumors of disaffection and growing discontent throughout the country on the rise, Ivan feared that other cities would soon follow the treasonous example of Izborsk. The proximity of the town to the cities of Novgorod and Pskov, coupled with the questionable implication of Novgorod's chancery administration in Teterin's plot, threw suspicion of treachery and defection onto the already distrusted city.
According to the Treaty of Tartu, the Russian-Estonian state boundary went eastwards of Izborsk and thus the town was part of Estonia from 1920 to early 1945 when, both Russia and Estonia being part of Soviet Union, the Russian SFSR/Estonian SSR boundary was moved westwards and thus Izborsk became part of the Russian SFSR.References:
The Porta Nigra (Latin for black gate) is the largest Roman city gate north of the Alps. It is designated as part of the Roman Monuments, Cathedral of St. Peter and Church of Our Lady in Trier UNESCO World Heritage Site. The name Porta Nigra originated in the Middle Ages due to the darkened colour of its stone; the original Roman name has not been preserved. Locals commonly refer to the Porta Nigra simply as Porta.
The Porta Nigra was built in grey sandstone between 186 and 200 AD. The original gate consisted of two four-storied towers, projecting as near semicircles on the outer side. A narrow courtyard separated the two gate openings on either side. For unknown reasons, however, the construction of the gate remained unfinished. For example, the stones at the northern (outer) side of the gate were never abraded, and the protruding stones would have made it impossible to install movable gates. Nonetheless, the gate was used for several centuries until the end of the Roman era in Trier.
In Roman times, the Porta Nigra was part of a system of four city gates, one of which stood at each side of the roughly rectangular Roman city. The Porta Nigra guarded the northern entry to the Roman city, while the Porta Alba (White Gate) was built in the east, the Porta Media (Middle Gate) in the south, and the Porta Inclyta (Famous Gate) in the west, next to the Roman bridge across the Moselle. The gates stood at the ends of the two main streets of the Roman Trier, one of which led north-south and the other east-west. Of these gates, only the Porta Nigra still exists today.
In the early Middle Ages the Roman city gates were no longer used for their original function and their stones were taken and reused for other buildings. Also iron and lead braces were broken out of the walls of the Porta Nigra for reuse. Traces of this destruction are still clearly visible on the north side of the gate.
After 1028, the Greek monk Simeon lived as a hermit in the ruins of the Porta Nigra. After his death (1035) and sanctification, the Simeonstift monastery was built next to the Porta Nigra to honor him. Saving it from further destruction, the Porta Nigra was transformed into a church: The inner court of the gate was roofed and intermediate ceilings were inserted. The two middle storeys of the former gate were converted into church naves: the upper storey being for the monks and the lower storey for the general public. The ground floor with the large gates was sealed, and a large outside staircase was constructed alongside the south side (the town side) of the gate, up to the lower storey of the church. A small staircase led further up to the upper storey. The church rooms were accessible through former windows of the western tower of the Porta Nigra that were enlarged to become entrance doors (still visible today). The top floor of the western tower was used as church tower, the eastern tower was leveled, and an apse added at its east side. An additional gate - the much smaller Simeon Gate - was built adjacent to the East side of the Porta Nigra and served as a city gate in medieval times.
In 1802 Napoleon Bonaparte dissolved the church in the Porta Nigra and the monastery beside it, along with the vast majority of Trier"s numerous churches and monasteries. On his visit to Trier in 1804, Napoleon ordered that the Porta Nigra be converted back to its Roman form. Only the apse was kept; but the eastern tower was not rebuilt to its original height. Local legend has it that Napoleon originally wanted to completely tear down the church, but locals convinced him that the church had actually been a Gaulish festival hall before being turned into a church. Another version of the story is that they told him about its Roman origins, persuading him to convert the gate back to its original form.
In 1986 the Porta Nigra was designated a World Heritage Site, along with other Roman monuments in Trier and its surroundings. The modern appearance of the Porta Nigra goes back almost unchanged to the reconstruction ordered by Napoleon. At the south side of the Porta Nigra, remains of Roman columns line the last 100 m of the street leading to the gate. Positioned where they had stood in Roman times, they give a slight impression of the aspect of the original Roman street that was lined with colonnades. The Porta Nigra, including the upper floors, is open to visitors.