In 1600, as Russia was entering a period of instability, the Commonwealth proposed a union with the Russian state. This failed move was followed by many other similarly unsuccessful, often adventurous attempts, some involving military invasions, other dynastic and diplomatic manipulations and scheming. While the differences between the two societies and empires proved in the end too formidable to overcome, the Polish–Lithuanian state ended up in 1619, after the Truce of Deulino, with the greatest ever expansion of its territory. At the same time it was weakened by the huge military effort made.