The meeting between Tsar Nicholas II and Kaiser Wilhelm II in the Gulf of Finland in July 1905

Tsar Nicholas II on board Kaiser Wilhelm's yacht Hohenzollern in 1905.

This photograph shows Tsar Nicholas II arriving at Kaiser Wilhelm II's yacht Hohenzollern on July 23, 1905. On the following day the Tsar signed the Treaty of Björkö (in Finnish Koivisto), a secret mutual defense accord with the German Empire, a treaty which was never to be ratified by the Russians. (And as a matter of fact the treaty was also rejected in Berlin.)

Below is an account of the event from Lamar Cecile's excellent book Wilhelm II: Emperor and Exile 1900 - 1941:

"At the end of October 1904, Wilhelm supplied the tsar with a draft alliance, and this led to a flurry of exchanges between the two sovereigns. What emerged from these negotiations was a treaty in which both powers provided the other with military aid in the event either was attacked in Europe or elsewhere. Nicholas, however, was unwilling to commit himself without first consulting his French allies, and Wilhelm's insistence that confidences were properly to be shared only between princes or rulers made no impression on the tsar. The matter therefore lay in abeyance as 1904 turned into 1905. The new year, however, brought a series of grave reverses for Nicholas II: the loss of Port Arthur on 2 January 1905; the colossal defeat of the tsar's Manchurian army at Mukden early in March; and finally, on 27 May, the annihilation in the Sea of Japan of the Russian fleet, which was laboriously making for Port Arthur. In addition, at the end of January 1905, Russia had exploded in what the Kaiser called the "Jew Revolution". Nicholas II's ability to resist Wilhelm's importuning to enter into an alliance was therefore considerably weaker than it had been during their negotiations in the fall of 1904, and he agreed to meet the Kaiser off the island of Björkö in the Gulf of Finland. After the Hohenzollern and the tsar's Polar Star dropped anchor off Björkö on 23 July 1905, Nicholas boarded the German yacht for dinner, in an unusual show of affability, stayed until 3 o'clock in the morning. He assured Wilhelm II, that with the Maroccan crisis defused by Delcassé's fall, there were no further barriers to Franco-German accord. Moreover, the tsar declared that he would never enter into an entente with England, most specifically not one directed against Germany. At nine the next morning, Wilhelm boarded the Polar Star, and he and the tsar retired to Nicholas II's cabin to affix the signatures to the so called  Björkö treaty."                                                   
   
However, as mentioned above, the Björkö Treaty was never ratified:

Although the treaty was signed by the Tsar, it was inevitably a "dead letter" because of Russia's commitment to France. The Russian statesmen Sergey Witte and Vladimir Lambsdorff, neither present at the yacht nor consulted beforehand, insisted that the treaty should never come into effect unless it was approved and signed by France. The Tsar gave in to their pressure, much to the consternation of the Kaiser who did not fail to reproach his cousin: "We joined hands and signed before God, who heard our vows!... What is signed, is signed! and God is our testator!"