Henry Fitzroy, DUke of Richmond and Somerset, bastard son of Henry VIII, was proposed at some point as a candidate for the Imperial vicariate as duke of Milan (at least that is my understanding of it). At another point in time, he was offered as a husband for an Austrian archduchess (or at least half-Austrian, since he was considered for both Maria of Viseu and Dorothea/Christine of Denmark). Now what if these two events coincide. But instead of marrying a legitimate princess, Karl V marries his bastard daughter, Margarethe, to Henry (now Duke Enrico I)?