The royal trip follows an invitation from President Abdullah Gul to visit the country and comes more than 36 years since the monarch and Philip last visited the secular Islamic republic.

The Queen and the Duke will lay a wreath at the tomb of Mustafa Kemal, the founder of modern Turkey, in the capital Ankara.

The royal couple will also formally meet the president at his palace, where his wife Hayrunnisa is expected to wear a controversial Islamic headscarf for the first time at an official event.

The move is likely to be seen as against Turkish law as headscarves are banned in public buildings and government offices and will antagonise the country's military who are defenders of Turkey's secular heritage.

In the evening a state banquet will be held in the Queen's honour.

The tour comes less than six months since the Prince of Wales visited Turkey and highlights the importance of Britain's relationship with the country.

Turkey is stepping up its campaign to join the European Union - a move which is supported by the UK.

The country has been pushing to become a member of the EU for many decades, becoming an official candidate in 1999 followed by formal accession negotiations in October 2005.

Geographically Turkey straddles both the east and west and is seen as an important ally for the international community in the fight against terrorism and the spread of Muslim extremists. In recent years it has also led the International Security Assistance Force fighting the Taliban in Afghanistan.