"We are taking people from the City who don't like working 24 hours a day, who want to work in a West End practice which is much more relaxed," explains Siegel.
Clintons has taken Angeline Tournier from Allen & Overy to focus on the private client side.
And Slaughter and May's Bernadette Thomas has been recruited to cover the commercial spin-off work.
Siegel admits Marks was the only person dedicated to private client work.
He says Clintons now aims to build the department to cash in on work coming in from new media and entertainment clients, including those which came with Maggie Rae and her department from Mishcon de Reya in February.
Andrew Young, Lawrence Graham's head of private client, says his firm is involved in an aggressive recruitment drive.
He describes Marks as a key recruit.
Marks says: "I was the private client side [at Clintons]. As far as I am aware the private client role hasn't been filled."
Marks says Lawrence Graham's City client base was a reason for the move.
She says: "I'll be building my offshore work and international connections."