sentences:  The company was established in 1988 by Peter Stas and Aletta Stas-Bax (a Dutch married couple).Before the sale to Citizen, Frédérique Constant SA was owned by Union Horlogère Holding B.V., which also owned Alpina Watches International SA, and Ateliers deMonaco SA, and was, in turn, owned by Frédérique Constant Holding SA.The company was founded in 1988 by Aletta Francoise Frédérique Stas-Bax and Peter Constant Stas (a Dutch married couple).