from wiki, defining the custodian thing:
Custodian of the Two Holy Mosques (Arabic: خادم الحرمين الشريفين), a historical term, was a pious title taken by some Caliphs and modern Saudi kings.
[edit] Saudi monarchy
It is most known today as the title taken by the King of Saudi Arabia in his role as protector of the two holiest cities of Islam, Mecca and Madinah, which had traditionally been the role of the Caliph (but soon the caliphate was to lose political control over the Arabian peninsula), later falling to the Grand Sharif of Mecca.
The first Saudi king to assume the title was Fahd bin Abdul Aziz in 1986. The current king, Abdullah bin Abdul Aziz, has taken the same title after the death of King Fahd in 2005. King Fahd replaced the term "His Majesty" with "Custodian of the Two Holy Mosques" because it was said that only God is All Majestic, therefore the term "His Majesty [The King]" was replaced with this term.
Some have claimed that this term was created by the Saudi monarchy so that it could try to replace the Caliphate. Opponents of the Saudi regime and Wahhabism claim that the Saudi monarch did not declare himself the Caliph because Saudis follow the Wahhabi sect of Islam, and such a move would thus be rejected by most Muslims[
|