Thousands of people gathered in Krakow on Sunday to pay respects at the state funeral of Polish President Lech Kaczynski and his wife Maria.
The ceremony was attended by several world leaders, although the air travel disruption caused by ash from volcano in Iceland kept others away.
US President Barack Obama and others were forced to abandon plans to attend, due to the air travel chaos.
German Chancellor Angela Merkel, French President Nicolas Sarkozy, Britain's Prince Charles and South Korean Prime Minister Chung Un-Chan also announced that they would not be able to attend for the same reason.
Russian President Dmitry Medvedev attended the ceremony, and leaders of other countries close to Poland, including the Czech Republic, Estonia, Hungary, Romania, Slovakia and Slovenia, took to the roads and railways to get to Krakow in time.
Sirens wailed to mark the start of the funeral mass at the Gothic Basilica of Our Lady in Krakow's central square, where huge crowds had gathered to see the service relayed live on giant screens on Sunday.
President Kaczynski, an often divisive nationalist in life, and his spouse Maria were laid to rest in the cathedral crypt of Krakow's hilltop Wawel castle where Poland's past kings and national heroes already lie.
The burial of Mr Kaczynski and his wife ended a week of mourning that began after they, and 94 other mostly senior figures, died in an air crash in Russia on 10 April.
The crash claimed the lives of much of Poland's elite, including the country's military chief, the heads of all three armed forces, the governor of the central bank and opponents of Poland's communist-era regime.
Mr Kaczynski's Tupolev Tu-154 jet slammed into a forest near Smolensk in western Russia - while en route to a ceremony marking the 70th anniversary of the massacre of thousands of Polish officers by Soviet forces.
On Saturday more than 100,000 mourners massed in Warsaw's main Pilsudski square for an emotional public memorial service for all the victims of the crash.