The Insterburg-Koenigsberg offensive operation was part of the East Prussian military campaign. The German command took all possible measures to prepare for continued resistance under siege conditions. In Koenigsberg there were numerous warehouses and arsenals, underground plants operated.
Features of the German defensive system
The invaders created three resistance rings. The first was located 6-8 km from the center of Koenigsberg. It included trenches, an anti-tank ditch, wire fences and minefields. There were 15 forts built in 1882. In each of them there were garrisons for 200-500 people. with 12-15 guns. The second ring passed along the outskirts of Koenigsberg. It housed stone structures, barricades, firing points on minefields and firing points. In the center of the city was the third ring. It included 9 bastions, ravelins and towers, built in the 17th century and rebuilt in 1843-1873. Koenigsberg itself belongs to the cities of mixed planning. Its central part was built back in 1525. Its structure is characterized as a radial-ring. Parallel layout prevailed on the northern outskirts, and arbitrary on the southern outskirts. Accordingly, the device of the German defense in different parts of the city was carried out in different ways. Forts, passing 6-8 km from the center, were located from each other at a distance of no more than 4 km. Between them fire communication was organized and trenches were equipped. A continuous anti-tank moat passed in separate sections. Its width was 6-10 km, and the depth was about three meters.

Additional protection
Along the circuit street in close proximity to the city center, the inner defense belt included full-profile trenches and 24 earthen forts. The latter were connected to each other by anti-tank ditches, which were half filled with water. The outer and inner defense zones were separated by two intermediate rings. In each of them there were 1-2 lines of trenches, bunkers, bunkers, which in some areas were covered by minefields and wire fences.
Firing points
The basis of internal defense was formed from strong points. They contacted each other with crossfire and covered themselves with powerful enough anti-tank and anti-personnel obstacles. Key strongholds were equipped at the intersection of streets in stone, the most durable and adapted for defense structures. The gaps formed between the strongholds were covered by barricades, gouges, rubble. For their construction used a variety of materials. Several points that had fire links with each other formed defense nodes. They, in turn, were grouped into lines. The organization of the fire system was carried out by adapting the structures to deliver dagger machine-gun and gun attacks. Artillery mounts and machine guns were located mainly on the lower floors, mortars, grenade launchers and machine gunners - on the upper.
Alignment of forces
The Koenigsberg operation of 1945 took place with the participation of troops of the 2nd and 3rd Belorussian fronts under the command of K.K. Rokossovsky and I.D. Chernyakhovsky, the 43rd army of the 1st Baltic Front, headed by I. Kh. The Soviet army from the sea supported the Baltic Fleet under the leadership of Admiral V.F. Tributs. In total, 15 combined arms, 1 tank armies, 5 mechanized and tank corps, 2 air armies took part in the hostilities. In January 1945, Koenigsberg was defended by a group of units "Center" (from 26.01 - "North"). The command was carried out by Colonel General G. Reinhardt (from 26.01 - L. Rendulich). Resistance from the German side was provided by 2 field and 1 tank armies, 1 - by the air fleet.
Command plan
The Koenigsberg operation, in short, involved cutting off the East Prussian group from the rest. Then it was planned to push it to the sea and destroy it. For this, the Soviet army had to strike simultaneously from the south and north in convergent directions. According to the command, a strike on Pillau was also planned.
Insterburg-Koenigsberg operation
Active actions of the Soviet troops began on January 13. The 3rd Belorussian Front broke the stubborn resistance of the Germans, broke through the defense on January 18 north of Numbinnen. The troops advanced 20-30 km deep. The 2nd Belorussian Front went on the offensive on 01/14. After a tense battle, the troops managed to break through the defenses and develop a swift offensive. At the same time, the 28th and 5th armies completed their breakthrough. On January 19, the 39th and 43rd armies captured Tilsit. During the battle, the enemy group was surrounded on Jan. 19-22. On the night of January 22, Soviet troops launched an assault on Interburg. The city was taken by morning. On January 26, troops reached the Baltic Sea north of Elisting. The key forces of the Germans were divided into separate groups. Part of the 2nd army managed to transfer for the Vistula to Pomerania. Destruction of enemy forces pushed to the sea was assigned to units of the 3rd Belorussian Front, which was facilitated by 4 armies of the 2nd Front. The rest of the forces were to carry out the Koenigsberg operation (photos of some moments of the battle are presented in the article). The second stage of the military campaign began on March 13.

Koenigsberg operation: operation progress
By March 29, Soviet troops destroyed the Heilsberg group. On April 6, the assault on Koenigsberg began. Parts of the 3rd Belorussian Front under the command of Vasilevsky took part in the battle. They were assisted by the Baltic Fleet. The Koenigsberg offensive was complicated by the presence of three defense rings. Before the assault, large-caliber artillery of ships and the front fired on the city and defensive fortifications for 4 days, thereby destroying the enemy’s long-term structures. The Koenigsberg operation itself began on April 6. The Germans offered stubborn resistance. But by the end of the day, the 39th Army managed to break into the enemy defenses for several kilometers. Troops cut the Konigsberg-Pillau railway. At this time, the 50th, 43rd and 11th guards. armies broke through the first defensive ring. They managed to come close to the walls of the city. Parts of the 43rd Army were the first to break into the fortress. 2 days after a stubborn battle, the Soviet troops managed to seize the railway junction and port, many industrial and military facilities. The first task that the Koenigsberg operation was to solve was to cut off the garrison from the forces located on the Zemland Peninsula.

The specifics of hostilities
When planning the stages of the Koenigsberg operation, the Soviet command first determined the starting line for the attack, where infantry and fire weapons were hidden. Then the battle formation was built, after which the tank units were pulled. Directly guided guns were installed at firing positions, passages in obstacles were organized. After that, tasks for rifle divisions, artillery and tanks were determined, and constant interaction of army units was also organized. After a short, but rather thorough preparation of the direct-pointing guns, a signal was fired from the spot at the firing points, walls and windows of the houses, embrasures for their destruction. The outskirts were subjected to decisive attacks by assault troops. They quickly advanced to the extreme structures. After a grenade attack, buildings were captured. Breaking into the outskirts, the assault squads advanced inland. Troops seeped through parks, alleys, gardens, courtyards, etc. Having seized separate quarters and structures, units immediately brought them into a defensive state. The strengthening of stone buildings was carried out. The structures on the outskirts facing the enemy were especially carefully prepared. In the districts occupied by the Soviet troops, strong points were equipped, circular defense was created, and commandants responsible for holding the points were appointed. During the first few days of the assault, combat aircraft carried out almost 14 thousand sorties, dropping about 3.5 thousand tons of bombs to defensive structures and troops.

German surrender
On April 8, the Soviet command sent parliamentarians to the fortress with a proposal to lay down their arms. However, the enemy refused, continuing resistance. By the morning of April 9, several parts of the garrison attempted to move west. But the actions of the 43rd Army, these plans were frustrated. As a result, the enemy was unable to escape from the city. From the Zemland Peninsula, units of the 5th Panzer Division attempted an attack. However, this counter strike was also not successful. Massive attacks by Soviet aircraft and artillery against the surviving German defense units began. Units of the 11th Guards. armies attacked Germans who resisted in the city center. As a result, on April 9, the garrison was forced to lay down their arms.
results
The Koenigsberg operation allowed the liberation of strategically important cities. The main units of the East Prussian German group were destroyed. After the battle, forces remained on the Zemland Peninsula. However, soon this group was liquidated. According to Soviet documents, about 94 thousand fascists were captured, about 42 thousand were killed. Soviet units captured more than 2 thousand guns, more than 1600 mortars, 128 aircraft. According to the results of the analysis of the situation conducted by G. Kretinin, about 25-30 thousand civilians were present in the total mass of prisoners who ended up in assembly centers. In this regard, the historian indicates the figure of 70.5 thousand German troops captured after the end of the fighting. The Koenigsberg operation was marked by salute in Moscow. Of the 324 guns were made 24 volleys. In addition, the leadership of the country established a medal, and 98 units of the army received the name "Koenigsberg". According to Soviet documents, losses in the Soviet troops amounted to 3,700 killed. G. Kretinin notes that the whole operation was organized and carried out "not by number, but by skill."

Conclusion
During the East Prussian campaign, Soviet soldiers showed high skill and exceptional heroism. They managed to overcome several powerful defensive rings, stubbornly and fiercely defended by the enemy. The victory in the operation was achieved through sufficiently lengthy battles. As a result, Soviet troops managed to occupy East Prussia and liberate the northern territories of Poland.