In the 1590s Covell took part in the controversy about how far the newly reformed Church of England should abandon the liturgy and hierarchy of the past, to which debate he contributed several broadly anti-puritan works. In his later career he allied himself with Archbishop John Whitgift and afterwards with his successor, Richard Bancroft, who like Covell was Lancashire-born.
Covell's interest to modern scholars now largely depends on one polemical work published in 1595, Polimanteia. In the course of this work, dedicated to the 3rd Earl of Essex, Covell briefly mentioned contemporary authors such as Thomas Nashe, Samuel Daniel and William Shakespeare.
- Stephen Wright, ‘Covell, William (d. 1613)’, Oxford Dictionary of National Biography, Oxford University Press, 2004
- "Covell or Cowell, William (CVL580W)". A Cambridge Alumni Database. University of Cambridge.
- Polimanteia, or, The meanes lawfull and unlawfull, to judge of the fall of a common-wealth, against the frivolous and foolish conjectures of this age, whereunto is added, a letter from England to her three daughters, Cambridge, Oxford, innes of court, and to all the rest of her inhabitants: perswading them to a constant unitie of what religion soever they are, for the defence of our dread soveraigne, and native cuntry: most requisite for this time wherein wee now live.