Hizb ut-Tahrir is a political party whose ideology is Islam, so politics is its work and Islam is its ideology. It works within the Islamic Ummah and together with her, so that she adopts Islam as her cause and is led to restore the Khilafah "Caliphate" and the ruling by what Allah revealed. Hizb ut-Tahrir is a political group and not a priestly one. Nor is it an academic, educational or a charity group. The Islamic thought is the soul of its body, its core and the secret of its life. Hizb ut-Tahrir started its work in al-Quds (Jerusalem) in 1953 under the leadership of its founder, the honourable scholar, thinker, able politician, and judge in the Court of Appeals in al-Quds (Jerusalem), Taqiuddin 
an-Nabhani.