Rachid Ghannouchi, the head of Tunisia's main Islamist Ennahda movement returns on Sunday to the country from which he was exiled 22 years ago.
Below are some facts on Ghannouchi and his party Ennahda.
* Ghannouchi is a respected Muslim scholar who went into exile in London in 1989. Now 69, Ghannouchi is widely considered to be a moderate who believes that Islam and democracy are compatible.
* Ennahda, which is Arab for Renaissance, was established in 1981 but was repressed by Tunisia's independence leader and former president Habib Bourguiba.
* Zine al-Abdine Ben Ali, who pushed Bourguiba aside in 1987, allowed Ennahda to take part in the 1989 elections. Ennahda officially won some 17 percent of the vote, coming second only to the ruling party. Some analysts say that there was widespread fraud in the election and that the true support for Ennahda was closer to 30-35 percent.
* Startled by Ennahda's popularity, Ben Ali banned the movement and cracked down on its members. Many went into exile and many more were jailed during the 1990s, accused of involvement in a plot to overthrow the secular state.
* Experts on Islamist movements say Ennahda's ideology is more moderate than that of groups such as the Muslim Brotherhood, the movement founded in Egypt in the 1920s. Ghannouchi himself has likened Ennahda to Turkey's AK Party, an Islamist-rooted party that has ruled since 2002.
* Ennahda plans to take part in Tunisia's parliamentary elections and analysts say it is likely to emerge as one of the strongest players on the Tunisian political scene. Ennahda does not plan to take part in presidential elections, however, and Ghannouchi does not plan to run for any public office.
"There is another generation, a younger generation, qualified for these positions," he told Reuters in an interview the day before his return.
* Tunisia has had a strong secular tradition since its independence from France in 1956. Both Bourguiba and Ben Ali discouraged women from wearing the Islamic veil and men from sporting long beards and enforced secular ideals.
As a result, Islamist politicians have a much lower profile than in nearby countries like Egypt or Algeria. It is not clear how widespread Ennahda's support is, however, because many Tunisians may have hidden their sympathies for years to avoid arrest.