On the death of the 8th Earl, a competition arose, both for the estates and for the title of Earl of Cassilis, between William, Earl of March and Ruglen, heir general, and Sir Thomas Kennedy of Culzean, 4th Baronet, the heir male.
Following the death of the 8th Earl, a struggle ensued for both the estates and the title of Earl of Cassilis, with William, Earl of March and Ruglen, heir general, vying against Sir Thomas Kennedy of Culzean, 4th Baronet, the male heir.