Question

the theme best expressed in to my dear loving husband and to the king’s most excellent majesty is

Explanation:

"To My Dear Loving Husband" expresses love for a spouse, and "To the King’s Most Excellent Majesty" shows respect/loyalty to a monarch. A common theme is love and devotion (romantic love in the first, loyal devotion in the second—both are forms of deep commitment).

Answer:

Love and Devotion (or similar, e.g., "Devotion to Loved Ones/Authority")