Not sure whats the story behind this claim, but came across this while searching some material for another thread in History forum.
Burke’s Peerage: Queen Elizabeth II Descended from the Prophet Muhammad | Informed Comment
Brooks-Baker said the British royal family is descended from Mohammed through the Arab kings of Seville, who once ruled Spain. By marriage, their blood passed to the European kings of Portugal and Castille, and through them to England’s 15th century King Edward IV. ‘
Queen Elizabeth II is descended from the Prophet Muhammad. - History - Interesting Facts and Fun Facts - OMG Facts
Revealing that the Queen was descended from Muhammad, the publishing director said ”The royal family’s direct descent from the prophet Mohammed cannot be relied upon to protect the royal family forever from Moslem terrorists.” The connection was a surprise to many, so he also added “It is little known by the British people that the blood of Mohammed flows in the veins of the queen. However, all Moslem religious leaders are proud of this fact.”
Where is Seville?
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
I think Seville is in Spain. So does that make her a syed? :halo:
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
Syeda Elizbath II 
Which king of Spain was descendent from the Prophet. As far as I know Spain always remained under Ummayad rule. 
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
its about time i file a court case to get my share from her property.
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
lodge a petition on facebook You have dual claim on British Government BTW. 
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
Even if she is related the royal family will never acknowledge this, as they know this will create problems for their image in the country.
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
You didn’t read the comment saying that this is for saving royal family from Muslim terrorists 
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
what do you think about this claim?
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
what could be the corelation?
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
May be they indirectly want to say that this will create a soft spot in Muslims, who hate west. Probably they don’t know about Karbala 
Re: Queen Elizabeth II is Descendent from Prophet Muhammad
All human beings are supposed to be descendants of one man. Then there should not be any problems in this world at all…