He was born in Coventry on 6 October 1942 and studied for his first degree and PhD at the University of Nottingham.
In 1968, he was appointed lecturer in English literature at Umea University in Sweden, but returned to England in 1971 to become head of English at what was then Thames Polytechnic.
After further posts as head of English at Middlesex University (1986-92) and head of historical and critical studies at what is now the University of Brighton (1992-93), he spent the remainder of his career at the University of Gloucestershire as professor and reader in English.
Committed to incorporating history and literary theory into English studies, Professor Widdowson became famous - and, in some quarters, notorious - for his edited volume Re-Reading English (1982), a book that proved central to fierce debates about the identity and future of the discipline.
He co-founded Literature and History, a journal he edited for 15 years, and co-authored the last three versions of A Reader's Guide to Contemporary Literary Theory (1996), a seminal and much-translated undergraduate textbook which is now in its fifth edition.
At the beginning of 2009, Professor Widdowson was awarded an emeritus professorship, although he continued to supervise doctoral students and to act as general editor of the Cyder Press, which he had set up to issue new scholarly texts and reprints of little-known literary works, especially those by writers with local connections.
He also recently completed a short autobiographical essay, "Snapshots from a Post-war Childhood", which was distributed by his family at his funeral.
Shelley Saguaro, head of humanities at Gloucestershire, said: "He was unstintingly generous as a mentor, and made a significant contribution to changing the discipline, establishing a completely new and radical approach to what history and literary studies had to say to each other.
"Although he offered close readings of authors from Thomas Hardy to Toni Morrison, he also adopted what one might call a cultural-studies approach, looking at material culture, always questioning the Canon, the state of English studies and what 'English literature' is."
Professor Widdowson died on 3 June 2009 and is survived by his wife Jane, their son, and a son and daughter from his previous marriage.
A forthcoming book, Literature as History: Essays in Honour of Peter Widdowson, edited by Simon Barker and Jo Gill, offers a further tribute to his eminent status within English studies.