The first mosques erected in early Muslim time did not have minarets – the believers were called to prayer by the muezzin standing on the mosque roof. But it is believed that with the expansion of Islam, the many churches with their towers paved the ground for adding towers to minarets as well. Most seem to agree that the lowest storey of the minaret in Kairouan are the remains of the first real minaret in the world, dating back to 730, more than 100 years after the death of the Prophet Muhammad. It is quite impressive even today, but note how much thicker it is than more recent minarets. It is 31.5 metres high with a base of 10.7 metres square. It consists of 3 sections, where the first is 19 metres, the second 5 metres and the third 7.5 metres including the dome.
