[1] On 31 July 1549, following his father's murder in Norwich during Kett's Rebellion, Sheffield, then aged 11, succeeded the Baronetage.

[3] As a minor in the King's guardianship, Sheffield was granted an annual annuity of 49 pounds, 2 shillings and 6 pence.

[5] On 8 June 1559 Queen Elizabeth I granted Sheffield license take possession of his inherited lands and their profits from when he turned 21.

[4][7] After his death, Douglas Howard became the lover of Robert Dudley, 1st Earl of Leicester and the favourite of Queen Elizabeth I.

The anonymous author of Leicester’s Commonwealth, the 1584 pamphlet attacking Dudley, suggested that while Sheffield's official cause of death was of natural causes (illness), there were rumours his death was the result of foul play, possibly orchestrated by Leicester to remove the obstacle to his relationship with Howard:[9]"Long after this, [Leicester] fell in love with the Lady Sheffield, whom I signified before, & then also had he the same fortune to have her husband die quickly with an extreme rheum in his head (as it was given out), but as other say of an artificial catarrh that stopped his breath."