Celebrations to mark the 80th anniversary of the Turkish Republic have been marred by a row between the country's fiercely secular establishment and the ruling Justice and Development Party, which has Islamist roots, over Islamic-style headscarves.
The row centred on the President's refusal to invite any headscarf-wearing wives of top officials, including the Prime Minister, to the official reception to mark the occasion.
The headscarf is considered a symbol of political Islam
Headscarves - regarded by secularists as symbols of radical Islam - are banned in official ceremonies, schools, universities and public offices.
The row has its roots in the way in which the Turkish Republic was established.
The formation of a Turkish Republic from the ashes of the old Ottoman empire in 1923 marked the beginning of massive political and social change.
Mustafa Kemal, later known as Ataturk, or father of the Turks, drove through a programme of westernisation.
He introduced a democratic parliamentary system. Religious laws were abolished and secularism became the cornerstone of the modern Turkish state.
The Arabic script used by Turks for a thousand years was swept aside. Modern Turkey adopted the Latin alphabet and Western calendar.
Turks were forced to take surnames and women were given full political rights.
After Ataturk's death in 1938, Turkey's powerful military, which launched three coups between 1960 and 1980, took on the role of guardian of a united, secular Turkish state.
In 1997, it helped to ease Turkey's first Islamist Prime Minister from power.
Today, Kemalism, as it is known, is still the dominant ideology and Turkey, a member of Nato and candidate for European Union membership, is increasingly westward looking.
But Ataturk would have been distinctly uneasy about the rise of political Islam over the past decade.
The current governing party, Justice and Development, has Islamist roots.
It stresses its support for secular democracy and its pro-Western outlook.
It has used its first year in power to drive through a raft of democratisation reforms, which it hopes will ease the way to eventual EU membership.
But as the latest row over headscarves demonstrates, the party still has an uneasy relationship with Turkey's secular establishment, which continues to view it with suspicion.