Sayyed Mohammad Al-Musawi,
Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to religious questions. In the past, he has also spent significant time in India guiding the community.
The main four Marja's in Najaf Ashraf are:
1. Aytullah Seestani who is followed by the majority of the Shia Muslims all over the world.
2. Ayatullah Sayyed Mohammad Saeed al-Hakeem.
3. Ayatullah Shaikh Eshaq al-Fayadh.
4. Ayatullah Shaikh Basheer al-Najafi.
The Marja' who is been followed by the majority of the Shia is called ( Al-Marja al-A'la) ( The highest Marja).
We have a system of our religious leadership based on highest degree of knowledge and piousness, which is quite different from Vatican.