What does "7th Earl of Cardigan" mean in the etymology explanation of cardigan?

1868, from James Thomas Brudenell (1797-1868), 7th Earl of Cardigan, English general distinguished in the Crimean War, who set the style, in one account supposedly wearing such a jacket while leading the Charge of the Light Brigade at Balaclava (1854). The place name is an anglicization of Welsh Ceredigion, lit. "Ceredig's land." Ceredig lived 5c.|||An earl is a title granted by the crown and is passed down to the eldest son. Thus the son of the gentleman granted the title of Earl of Cardigan is the 2nd earl. The son of the 2nd earl is the 3rd earl and so on.