George Clooney and Amal Alamuddin will invite only 60 close family and guests at their private Island wedding ceremony in Venice, it has been reported.
Human rights barrister's paternal aunt, May Salman, and her children Ramzi and Makram are apparently integral to proceedings, the Mirror reported.
The 53-year-old's best man has still not been disclosed, but newlywed Brad Pitt, Matt Damon and Cindy Crawford's husband Rande Gerber are all rumoured to be in contention. Other guests include Julia Roberts, Sandra Bullock and Jennifer Aniston.
US President Barack Obama has not been invited as he has "more important things to do".
The editor of American Vogue, Brit Anna Wintour, would also be going and has been expected to feature the wedding in an upcoming edition of her magazine.
The couple is then expected to host a final banquet on October 25 at Danesfield House in Medmenham near Marlow, Buckinghamshire.