Shelton's dedication of his major literary work to Theophilus Howard has led to speculation as to the connection between them. The Oxford Dictionary of National Biography suggests they could have met in the Low Countries in 1610. Another suggestion is that the connection was via Lady Suffolk, Theophilus' mother. According to Alexander T. Wright, in a paper published in October 1898, Lady Suffolk had three relatives bearing the name Thomas Shelton, and the author may therefore have been related. Moreover, Lady Suffolk received money from the King of Spain on the recommendation of the Spanish ambassador. She was of interest to the Spanish because of her perceived influence on the Earl of Salisbury.