Four days after the battle of the Yellow Sea, the Vladivostok squadron, consisting of the splendid cruisers Rurik, Rossia, and Gromvoi—for the other cruiser, Bogatyr, had run on the rocks near the harbor—which had more than once eluded Admiral Kamimura, were finally discovered by him north of the Tsushima Island. After a lively engagement the Rurik was sunk, and the other two Russian cruisers narrowly escaped to Vladivostok.

During these six months between February and August, the Japanese army on land in three different corps had been steadily advancing toward Liao-yang. The first corps, under Lieutenant General Kuroki, which landed at Korean ports, had encountered no serious opposition on its march through the peninsula, until it reached the Yalu River on the frontier. There took place on the last days of April and May 1 the first important land battle between the contending armies. The Russian forces under Zassulitch were overpowered by the superior artillery of the enemy, and, after a desperate fight and disastrous retreat, fell back to Feng-hwang-cheng, which again was abandoned on May 6. Then, taking Sai-ma-tsi on June 7 after several attempts, Kuroki came to the difficult pass of Mo-tien-ling, which he captured on July 4 after a hard fight, and which the Russians made a costly, but unsuccessful, effort to retake on July 17. Chiao-tow fell on July 19, and Yu-shu-lin-tsu and Yang-tsu-ling on August 1. From the end of August, Kuroki coöperated with the two other army corps which had simultaneously been closing upon Liao-yang. Of these, the second corps, under Lieutenant General Oku, landing on May 5 at Pi-tsu-wo on the northeastern coast of the Liao-tung peninsula, immediately took Pu-lan-tien, and, after a sixteen-hour battle of the most desperate character, had driven the enemy toward Port Arthur from Kin-chow and Nanshan Hills on May 26. These actions completely cut the forces at Port Arthur from the rest of the Russian army in Manchuria. General Kuropatkin, commanding the army, however, now possessed nearly 100,000 men south of Liao-yang, and, yielding to the impossible request from St. Petersburg that he should make a supreme effort to relieve Port Arthur, dispatched General Stakelberg with perhaps 44,000 men on this difficult mission. He was attacked on June 13 at Telissu by General Oku's army of a nearly equal size, and, after a savage battle of artillery fire and bayonet charges, was forced back with heavy losses. Stakelberg's retreating army offered gallant resistance to the Japanese at Hiung-yo-cheng on June 21, at Kai-ping from July 6 to 9, at Taping-ling and Tashi-chiao from July 24 to 29, and at Tomu-cheng between July 31 and August 1. At the later stage of these engagements Oku's forces coöperated with divisions of the third army corps, under General Nodzu, which had landed at Ta-ku-shan on May 19, and had captured Siu-yen on June 8 and Feng-shui (Wafangao) Pass on June 27. The fall of Anshan-chan on August 27 to the second corps practically opened the great battle of Liao-yang, the military center of southern Manchuria, to which General Kuropatkin had retired.

The battle of Liao-yang while not the greatest, was in some respects the most desperate, engagement of the war. The Japanese forces, under the supreme command of Field Marshal Ōyama (who had arrived at Dalny on July 20), probably numbered 240,000 men, with 800 guns, and the Russian, under General Kuropatkin, perhaps 200,000 men, with 572 guns. The defenses around and in the city were most elaborate and extensive. The Japanese attack was begun a little before its plans had completely matured, and, for nearly a week, a complex series of fierce and determined fightings raged in front of the walled city. On August 31 a part of Kuroki's army crossed the Taitsu River and began its flanking movement, and, against the determined effort of Kuropatkin to annihilate this section of the Japanese, Kuroki succeeded after three days of action in sending his entire forces across the stream. On September 4 Kuropatkin set the city on fire, and, by a masterly retreat, extricated the remainder of his army from a threatened closure by Kuroki's divisions, the entire Russian forces reaching Mukden September 20. He had lost nearly 25,000 men, and Ōyama half of that number.

Heavy rains now intervened. Kuropatkin at Mukden proclaimed that his forces were now for the first time strong enough to begin a forward movement against the enemy. With nine army corps he advanced southward on October 5, easily taking the railway station by the Sha River and also the defenses of Bentsiaputse to the east. The cavalry outposts also scored a few minor victories. Ōyama also now decided to take the offensive, and marched forward with a wide front extending over fifty miles from east to northwest to the Hun River. Both sides tried flanking movements, none of which proved decisively successful. In the heavy fighting which lasted till the 17th, in which the Russian and Japanese losses probably amounted, respectively, to 69,000 and 13,300, Kuropatkin was definitely forced back, and his original purpose to turn the tide of the war failed. This is known as the battle of the Sha River.

In the meantime, ever since General Nogi landed early in June and at once began desperate attacks on the outer forts, Port Arthur had been a scene of prodigious acts of heroism by both the besiegers and the besieged. Points were taken and retaken, and hundreds lost their lives at each explosion of mines or terrific cannonading from the surrounding forts. In the midst of this series of engagements, however, officers and men of the hostile armies frequently met together to arrange for the recovery of the dead bodies, always fraternizing in kindly spirit. The besieging army steadily closed in, and, in the outer line of forts having been reduced, the 203-Meter Hill of the western inner forts was at length captured, on November 29-30. From this point Japanese shells could sweep over the harbor. This was followed by the fall of the eastern forts of Sung-shu and Ki-kwan, on December 19, which were blown up by mines laid by the besiegers in tunnels dug directly under the feet of the enemy. When ten days later the Erlung fort was taken, the position of the gallant General Stoessel's defending army was no longer tenable. He capitulated on January 1, 1905, with his remaining army of nearly 25,000 men, and surrendered fifty forts and 546 guns to the Japanese army. The war vessels in the harbor had, however, been blown up and sunk by the Russians before the surrender of the forts. Officers, including Stoessel, who wished to return were allowed to depart on parole with their side-arms. In their informal meeting, on January 4, Generals Nogi and Stoessel lauded the high qualities of each other's army, the latter visibly moved by the news that Nogi had lost his two sons in the war. Stoessel, with his wife and a few officers, left Nagasaki on January 17 on their homeward voyage.

The Japanese veterans at Port Arthur, probably 50,000 or 60,000 in number, were now ready to march northward to join Ōyama's army. Before their arrival at the front, however, a severe battle took place in the heart of winter, from January 25 to 31, at Hokau-tai, on the Hun River, between General Grippenberg's second Russian army and Ōyama's forces. The result was not a decisive gain to either side, but the Russians lost twice as many men as the Japanese, nearly 15,000 of their numbers being killed and wounded. It was after this battle that Grippenberg openly declared his disagreement with his chief Kuropatkin, and resigned his command and was succeeded by General Kaulbars.

With the addition of Nogi's army to the left of Oku's, and of General Kawamura's to the right of Kuroki's, Ōyama now commanded five corps in sixteen divisions, numbering at least 400,000 men and occupying a front of nearly a hundred miles. This colossal army tried conclusions with the at least 350,000 men under Kuropatkin at Mukden in what was probably the greatest battle or series of battles in the history of the world. The engagements began on February 20 and continued till March 16, resulting in a decisive defeat of the Russians. Until March 7 Kuropatkin's left was harassed by Kuroki, and his right was defending itself desperately against the flanking movement of Nogi, while his center, under Linevitch and Kaulbars, together with Rennenkampf's Cossacks, took a determined stand against the onslaught of Nodzu and Oku. The retreat was ordered on the night of this day, for a further delay would cause Kuropatkin's divisions to be surrounded and annihilated. The Japanese closely pursued the fleeing enemy, and gave him no time to rally before crossing the Hun River. The blinding dust storm and the biting cold of March 9 did not greatly detract from the rigor of the pursuit. Mukden was entered by Ōyama early on March 10, and the strong defense and the great colliery at Fushun to the east were taken the next day. The Russians now retired to Tie-ling, forty miles to the north, in a complete rout, Linevitch's army alone making an orderly retreat. Tie-ling was also taken on the 16th, the Russians receding further north. Their losses probably aggregated 150,000 men, or more than forty per cent. of the entire army, while the Japanese lost about one-third as many in killed and wounded. The tsar at once convoked a war council, and resolved to dispatch to the East another Russian army of 450,000 men. The day after the fall of Tie-ling, he telegraphed Kuropatkin and, without a word of praise, transferred the latter's command over the Manchurian army to Linevitch. Kuropatkin retired to Harbin, and then returned to serve under the new commander-in-chief.

The Baltic fleet of Russia, the departure of which for the East had been announced several times, at last started from Kronstadt in the middle of October, 1904, under Vice Admiral Rozhestvenski. Having been aroused to a state of nervous apprehension by the unfounded rumor that Japanese torpedo boats were in European waters, some officers of the Russian fleet fancied that they descried two of these small war vessels among the British fishing boats at Dogger Bank in the North Sea, on the night of October 21, and fired upon them, sinking a trawler, killing two fishermen, and injuring several others. The fleet then proceeded south at full speed. It had also attacked, at different times, a Swedish, a Norwegian, a Danish, and a German ship. When the news of the Dogger Bank incident reached Hull on the 24th, all England was aflame, and the more radical people counseled war with Russia. Owing to the calmness of the British government, however, and also to the assistance of France, the matter was referred to the investigation of an international court of naval experts. The latter published the opinion of its majority, on February 25, 1905, that the firing was unjustifiable and unduly prolonged, but that it did not impair the military valor and the humanitarian sentiment of the Russian admiral and his staff.

Soon after the North Sea incident the Baltic fleet was divided into two sections, one under Admiral Voelkersam going by way of the Suez Canal and the other under Rozhestvenski himself rounding the Cape of Good Hope. The two squadrons reunited in January in the Indian Ocean, and drilled their raw crews near the French Island of Madagascar. A third section, under Admiral Nebokatov, left Libau on February 15, and joined the main squadron before it entered the Chinese waters. The stay of the fleet near Saigon and Kamranh Bay, French Indo-China, raised delicate questions as to the rights of the hostile vessel in a neutral harbor, but a friction was averted by the tardy, but definite, action taken by the tsar and the French government in ordering away the Russian fleet from the French territorial waters. Near the end of May the entire fleet was headed toward its final destination.