Marquis Dublin is in Marquis and Marquess Ireland.
On 1st December 1385 Robert de Vere 1st Duke Ireland [aged 23] was created 1st Marquis Dublin. Philippa de Coucy Duchess Ireland [aged 18] by marriage Marchioness Dublin.
In 1387 Robert de Vere 1st Duke Ireland [aged 24] and Agnes Launcekrona Duchess Ireland were married. She by marriage Duchess Ireland, Marchioness Dublin, Countess of Oxford. He the son of Thomas de Vere 8th Earl of Oxford and Maud Ufford Countess of Oxford [aged 42].