February 8–9, 1904 · Liaodong Peninsula Theater

Without a formal declaration of war, Admiral Tōgō launched a torpedo boat destroyer attack on the Russian Pacific Squadron anchored at Port Arthur on the night of February 8–9, 1904. The surprise assault damaged several Russian battleships and immediately established Japanese naval superiority in the theater. The attack shocked the world and set the tone for a war fought with modern industrial weapons and ruthless strategic initiative.

May 1, 1904 · Korea Theater

The first significant land battle of the war saw General Kuroki Tamemoto's Japanese First Army cross the Yalu River under fire and defeat Russian forces defending the Korean-Manchurian border. Kuroki used the island of Kiuriendao as a staging point, constructed bridges under darkness, and launched coordinated assaults that overwhelmed Russian defensive positions at Chiu-lien-ch'eng. The Russian Eastern Detachment, outnumbered and outmaneuvered, suffered a stinging defeat and was forced to withdraw northward into Manchuria.

June 14–15, 1904 · Manchuria Theater

Following the Japanese capture of Nanshan, General Stackelberg led the Russian 1st Siberian Corps southward to relieve Port Arthur. At Telissu (also called Vafangou), General Oku's Second Army met the Russians in open battle. The Japanese executed flanking maneuvers that threatened Russian encirclement, forcing Stackelberg into a costly retreat northward. The defeat ended any hope of relieving the besieged garrison at Port Arthur by a direct overland thrust.

August 1 – January 2, 1904–1905 · Liaodong Peninsula Theater

The five-month siege of Port Arthur was the most brutal episode of the entire war. General Nogi Maresuke's Third Army conducted massed infantry assaults against modern concrete fortifications, suffering catastrophic losses in frontal attacks on positions like 203 Metre Hill. The Russian garrison, inspired by the brilliant defensive genius of General Kondratenko, repulsed wave after wave. When Kondratenko was killed in December, morale collapsed. General Stoessel surrendered the fortress on January 2, 1905, a decision later deemed treasonous by Russian courts.

August 25 – September 3, 1904 · Manchuria Theater

The largest battle of the war to that point, Liaoyang saw three Japanese armies converge on the major Russian base. Kuropatkin's forces initially held strong defensive positions, even launching limited counterattacks. But when General Kuroki's First Army succeeded in crossing the Taitzu River north of the city and threatened the Russian line of retreat, Kuropatkin ordered a withdrawal to Mukden. The retreat, though conducted in reasonable order, was a major strategic defeat that ceded southern Manchuria to Japan.

October 5–17, 1904 · Manchuria Theater

Seeking to recover the initiative, Kuropatkin launched a major offensive south of Mukden along the Sha-Ho River. Initial Russian advances pushed the Japanese back and briefly threatened to cut their supply lines. But coordination failures between Russian corps commanders allowed Oyama to stabilize the front and then counterattack. Both sides exhausted themselves in brutal fighting across broken terrain. The battle ended in mutual exhaustion, with neither side able to deliver a decisive blow, but the Russians had briefly held the offensive.

January 2, 1905 · Liaodong Peninsula Theater

On January 2, 1905, General Stoessel shocked both Russia and the world by surrendering Port Arthur while the garrison still held defensive capacity and supplies for continued resistance. The fortress fell after 156 days of siege following the death of its true defender, General Kondratenko, in December. Stoessel met with General Nogi and signed the articles of surrender, handing over approximately 24,000 surviving soldiers as prisoners of war. Japan's Nogi, who had lost two sons in the siege, wept openly — though whether from grief at his sons or respect for the fallen enemy remained a subject of Japanese legend.

January 25–29, 1905 · Manchuria Theater

In the depths of a Manchurian winter, General Gripenberg's Second Manchurian Army launched a surprise offensive on the Japanese left flank at Sandepu. The attack initially achieved surprise and penetrated Japanese lines before Kuropatkin, fearing overextension and a Japanese counterattack elsewhere, halted the offensive just as it approached a breakthrough. Gripenberg, furious at the lost opportunity, resigned his command and returned to Russia, where he publicly blamed Kuropatkin for squandering the best Russian offensive opportunity of the war.

February 19 – March 10, 1905 · Manchuria Theater

The largest land battle in history to that point, Mukden involved over 600,000 men across a front stretching nearly 100 kilometers. Oyama and Kodama executed a massive double-envelopment, swinging five armies around the Russian flanks in a Manchurian winter. Despite fighting tenaciously, Russian forces were outmaneuvered as Japanese columns threatened encirclement from both sides. Kuropatkin ordered a desperate retreat northward through a narrowing corridor, managing to escape annihilation but losing the city of Mukden and suffering catastrophic casualties. The retreat lasted weeks, with the Russian army dissolving into near-chaos.

May 27–28, 1905 · Korea Strait Theater

The most decisive naval battle since Trafalgar, Tsushima was the culmination of Russia's extraordinary 18,000-mile voyage of the Baltic Fleet around the world to relieve the Pacific Squadron — only to find Port Arthur already fallen. Admiral Tōgō intercepted Rozhestvensky's exhausted fleet in the Korea Strait and executed the famous 'crossing of the T,' bringing his full broadside to bear on the Russian line. In two days of fighting, Japan sank or captured virtually the entire Russian fleet. Of 38 Russian warships, 21 were sunk, 7 captured, and 6 interned. Only 3 escaped to Vladivostok. Russian casualties dwarfed Japanese losses by a ratio of nearly 180 to 1.

September 5, 1905 · Diplomatic Theater

Mediated by U.S. President Theodore Roosevelt at the Portsmouth Naval Shipyard in New Hampshire, the peace negotiations concluded a war both sides were exhausted by. Japan, despite its military victories, was financially strained and unable to continue offensive operations. Russia, wracked by revolution at home, also needed peace urgently. Count Witte, Russia's chief negotiator, skillfully prevented Japan from extracting an indemnity — a concession that outraged Japanese public opinion and sparked riots in Tokyo. Japan received southern Sakhalin, the Liaodong Leasehold, and recognition of its paramount interest in Korea.