Plyos Fortress

The Second Fortress (1410)

In the early 15th century, the Moscow principality was actively engaged in centralizing power and strengthening its positions amidst the weakening of the Golden Horde and internal political instability in Russia. An important step in this process was the construction of a new Plyos fortress in 1410 at the initiative of Grand Duke Vasily I Dmitrievich of Moscow (son of Dmitry Donskoy). Seeking to strengthen the Moscow principality and ensure control over key trade routes, Vasily I saw the strategic significance of Plyos as an important stronghold on the Volga and "ordered the city of Plyos to be built". This marked the official beginning of the city of Plyos.

The Plyos fortress was built to strengthen Moscow's positions in this key area and to protect an important trade route connecting the North and South of Russia. This fortress became part of an extensive system of customs and defensive structures designed to control the Volga and ensure Moscow's influence over trade flows.

Architectural Features

The second Plyos fortress was a wooden citadel surrounded by a high earthwork and located on an elevation above the Volga. The fortress was built on Cathedral Hill, providing a strategic advantage and control over a significant section of the river.

The fortress walls were reinforced with signal towers and observation posts, forming a network of "signal axes". The main signal axis connected Plyos with the village of Storozhevo, from where it was possible to observe movement along the Volga for more than 20 kilometers upstream. This allowed for early detection of enemy approach.

The defensive system of the fortress included a massive earthwork on the southern side, 170 meters long, 6 meters high, and 29 meters wide. This earthwork created a significant obstacle for attackers. Inside the earthwork, walls were erected, consisting of multi-layered structures. The outer part of the walls was made of hewn pine logs, and the inner space was filled with bricks and stones, enhancing the defensive properties.

The northern tower of the fortress had two layers of walls, with a layer of bricks in between, providing additional protection. The towers were square, built from logs up to 20 cm in diameter and up to 9 meters long, as well as brickwork for added strength.

Customs Function

Besides its defensive function, Plyos also played an important role in customs control. The fortress served as a point for collecting duties for passage along the Volga, allowing control over trade flows and providing income for the Moscow principality. Control was especially important in the context of increasing competition with Novgorod, which sought to control Volga trade.

According to "Journey Beyond Three Seas" by the Tver merchant Afanasy Nikitin, Plyos maintained its importance as a trade and customs center even more than 60 years after its construction.

Destruction of the Fortress

The wooden fortifications of Plyos were designed for long-term use, but they apparently stood only until the Kazan Tatars' invasion, and in 1429 the city was ravaged and burned by the Kazan prince Mahmud Khazi: "...the Kazan Tatars came to Galich without warning..., took Kostroma, and ravaged Plyos and Lukh". Archaeological data confirm extensive destruction: the fortress's structure was severely damaged by fire, and the remains of wooden and brick structures fell into decay.