From Atonia Fraser's The Wives of Henry VIII, pg 363:
The following genealogy should be seen as a reflection of the narrowness of aristocratic society in a world of small population, rather than as some unconscious desire [that King Henry VIII might have] to commit forms of incest as has been suggested. The wives of Henry VIII were not "closely" related or to King Henry himself. The exception would be of the first cousins Anne Boleyn and Catherine Howard; Henry's 2nd and 5th wife whom shared the same grandfather, Sir Thomas Howard, 2nd Duke of Norfolk by his 1st wife Elizabeth Tilney (herself the daughter of Elizabeth Cheney by her first husband Sir Philip Tilney. Elizabeth married secondly Sir John Say. Her daughter Anne would become grandmother to Queen consort Jane Seymour, thus making Queen Anne, Queen Jane, and Queen Catherine Howard second cousins).
Katherine Parr was a maternal 3rd cousin, once removed and and a paternal 4th cousin, once removed of her 3rd husband, King Henry VIII. Queen Katherine Parr was of royal Lancastrian blood. Unlike all the other queen consorts, Katherine was the only queen consort of Henry to have descended from the Beaufort family (eventually legitimized children of Prince John of Gaunt, 1st Duke of Lancaster and mistress, later wife, Katherine Roet) through which King Henry VII claimed his throne. Katherine descended from Lady Joan Beaufort and her second husband Sir Ralph Neville, 1st Earl of Westmorland. Henry and Katherine had Lady Joan Beaufort (only daughter of John of Gaunt and Katherine) and Sir Ralph Neville in common as his maternal great-grandmother was their daughter Cecily Neville, Duchess of York; sister of Katherine's great-great grandfather Sir Richard Neville, 5th Earl of Salisbury. Sir Richard Neville, 5th Earl of Salisbury --discussed later on-- was the husband of Alice Montacute, suo jure 5th Countess of Salisbury. Alice's mother, Lady Eleanor Holland was the sister of King Henry's paternal great-great-grandmother, Margaret Holland, wife of Sir John Beaufort, 1st Earl of Somerset (grandfather of Henry VIII's grandmother, Lady Margaret Beaufort) again making them paternal 4th cousins, once removed.
|Lady Joan Fogge, grandmother of Queen Katherine Parr|
|FitzHugh coat of arms|
|King Richard III and Lady Anne Neville|
|Richard Neville, 5th Earl of Salisbury|
|Sir Thomas Montacute, 4th Earl of Salisbury and Lady Eleanor Holland|
|Sir Richard Neville, Earl of Warwick and Salisbury|
|Lady Margaret Beaufort|
|John of Gaunt, 1st Duke of Lancaster and Katherine Roet|
|Contemporary portrait of Lady Cecily Neville, Duchess of York|
|Queen Regent, Joan I of Navarre|
|Prince Thomas of Woodstock, Earl of Norfolk and Alice Hayles|