Its primary mission is to protect the Iraqi leader and secure Baghdad, the Iraqi capital. It has military and intelligence responsibilities.
This force is seen as a crucial pillar maintaining Saddam Hussein in power.
SRG soldiers tend to be recruited from in and around Saddam Hussein's home town of Tikrit.
The clans in these areas have shown great loyalty to Saddam Hussein and his regime.
The SRG is the only significant military unit allowed into central Baghdad, apart from the intelligence services' military branches.
The SRG was at the centre of disputes between Iraq and the UN weapons inspectors in 1998, when the Iraqi authorities refused access to its facilities where proscribed weapons were believed to have been stored.
As troops are waging a ground war as part of the US-led campaign to remove the Iraqi leader, some military analysts believe US and UK soldiers might have to confront the SRG in street by street fighting in Baghdad.