Lech Aleksander Kaczyński (born June 18, 1949, in Warsaw, died April 10, 2010) was a Polish lawyer, politician, and activist who served as President of Poland from 2005 until his death in 2010. He was the identical twin brother of fellow politician Jarosław Kaczyński, with whom he co-founded the Law and Justice (PiS) party. Kaczyński studied law at the University of Warsaw and the University of Gdańsk, specializing in labor law, and earned a doctorate from the University of Warsaw. He began his career as a research assistant and lecturer from 1971 to 1997. As a young activist in the 1970s, he joined the opposition against the communist regime and supported the Solidarity trade union movement during the Gdańsk strikes. His political career advanced after the fall of communism, serving as President of the Supreme Audit Office (1992–1995), Minister of Justice and Public Prosecutor General (2000–2001), and Mayor of Warsaw (2002–2005). Elected president in 2005, he advocated for conservative values, Polish sovereignty in the EU, strong ties with the United States, and historical memory, such as commemorations of the Katyń massacre. He died at age 60 in the Smolensk air disaster on April 10, 2010, while en route to commemorate the 70th anniversary of the Katyń massacre, an event that sparked national mourning and ongoing investigations. Kaczyński was posthumously honored for his contributions to Polish democracy and international relations.