The Soviet Treaty of Friendship, Cooperation, and Mutual Assistance was signed in the capital city of this country, and various (*) partitions divided up the land owned by Lithuania and this country.
The Piast Dynasty was the first family to unify this country, whose Battle of Legnica halted Mongol incursion into this nation, but ended with the death of Henry II of Silesia. The Soviet Treaty of Friendship, Cooperation, and Mutual Assistance was signed in the capital city of this country, and various (*) partitions divided up the land owned by Lithuania and this country. One organization in this country was founded at a Gdansk Shipyard and called "Solidarity" by Lech Walesa, and helped lead to its liberation from the USSR. For ten points, name this country, which saw its president Lech Kaczynski recently die in a plane crash, leading to a new leader in Warsaw.
The Piast Dynasty was the first family to unify this country, whose Battle of Legnica halted Mongol incursion into this nation, but ended with the death of Henry II of Silesia.
Republic of {Poland}