Lech Kaczynski, 60, built his political career as a right-wing nationalist by battling Russian influence in Poland and cultivating the memory of the suffering his country endured during world war two. He died Saturday morning outside the western Russian city of Smolensk, on his way to a memorial service at the Katyn forest, where 70 years ago the Soviets executed more than 4,000 Polish officers.
Kaczynski was elected president in 2005 on a platform of restoring Poland's national pride, battling what he saw as the baleful influence of big business and the communist-era secret police on Polish public life, and slowing market-oriented reforms he felt were harming Poland's poorest and most vulnerable.
The first two years of his presidency marked the apogee of influence for the right-wing Law and Justice party (PiS) he founded in 2001 with his twin brother Jaroslaw, as the the party formed the government and his brother became prime minister.
Parliamentary elections in 2007 brought the centrist Civic Platform government led by Donald Tusk, the current prime minister, to power, igniting a conflict over everything from who should represent the country at foreign summits, to the direction of economic and foreign policy that Kaczynski lost, which left the presidency much weaker than the government.
Kaczynski, in private a warm and often witty man, had a thin-skinned public persona that did not handle criticism well.
Kaczynski, whose parents fought against the Germans during the war, had a traditional patriotic and Roman Catholic upbringing. His first brush with fame came when he and his brother were 12, and were cast as the freckle-faced stars of a popular film: “Two boys who stole the moon”.
He entered opposition politics in 1976, and was a senior advisor to the Solidarity labour union, formed in 1980. He was interned by the communist authorities after martial law was declared in 1981, but after his release continued to be involved in the anti-communist underground as a close ally of Lech Walesa, the union's leader.
Kaczynski took part in the 1989 round-table negotiations that led to the end of communist rule that summer. He fell out with Mr Walesa in 1991, by then Poland's president. The Kaczynski twins were sidelined, and only began their return to power in 2000, when Lech was unexpectedly made justice minister in the centre-tight government of the time.
His hard-line approach to law enforcement struck a chord with public opinion increasingly dismayed at frequent high-level corruption, and Kaczynski became one of the country's most popular politicians. Elected mayor of Warsaw in 2002, his priority was the construction of a museum honouring the 1944 Warsaw uprising against the Germans.
He also twice banned a gay pride parade from taking to the streets of Warsaw, which enormously appealed to his traditionalist right-wing electorate. It was that Catholic and nationalistic support that led him to victory in the 2005 presidential elections.
As president, Kaczynski devoted enormous energy to events like the commemoration of the Katyn massacre, as well as trying to weaken Russian influence in Ukraine, Georgia and other ex-Soviet republics, something he saw as key to strengthening Poland's long-term security.
In 2008, he travelled to Tbilisi, the embattled capital of Georgia which was then fighting Russia, in order to demonstrate his support for Mikheil Saakashvili, Georgia's president. During that flight the pilot refused to land in Georgia for safety reasons, and, despite entreaties from the president, instead landed in neighbouring Azerbaijan.
Kaczynski also had an ambivalent view of the European Union, worrying about the loss of Poland's distinctiveness and fearing the rise of German influence. In the end, he helped negotiate the Lisbon treaty reforming the functioning of the EU, but later baulked at signing the pact.
Towards the end of his presidency, Kaczynski had seen his support shrivel to about a fifth of the electorate, and he looked certain to go down to defeat against Bronislaw Komorowski, the speaker of parliament and Civic Platform candidate in elections originally scheduled for this autumn.
Kaczynski's wife, Maria, an economist who softened his public image and was one of the country's most popular public figures, died with him in the air crash. They leave behind a daughter, Marta, and two grandchildren.