Macy’s Chairman, President and CEO Terry Lundgren is scheduled to testify in New York State Supreme Court on Monday in a trial that pits the department store chain against rival J.C. Penney Co. over a partnership with home diva Martha Stewart.

The trial focuses on whether Macy’s has the exclusive right to sell Martha Stewart-branded products in such categories as cookware, bedding and bath.

Other key witnesses expected to take the stand this week include Martha Stewart and Penney’s CEO Ron Johnson.

Macy’s has argued in court documents that Martha Stewart Living breached a long-standing contract when it penned a deal in December 2011 to open Martha Stewart mini shops in most J.C. Penney stores beginning this spring.