Rather than write a history, Camden wanted to describe in detail the Great Britain of the present, and to show how the traces of the past could be discerned in the existing landscape.

He drew on the published and unpublished work of John Leland and William Lambarde, among others, and received the assistance of a large network of correspondents with similar interests.

He also travelled throughout Great Britain to view documents, sites, and artefacts for himself: he is known to have visited East Anglia in 1578, Yorkshire and Lancashire in 1582, Devon in 1589, Wales in 1590, Salisbury, Wells and Oxford in 1596, and Carlisle and Hadrian's Wall in 1599.

By this time, largely because of the Britannia's reputation, he was a well-known and revered figure, and the appointment was meant to free him from the labour of teaching and to facilitate his research.

The appointment, however, roused the jealousy of Ralph Brooke, York Herald, who, in retaliation, published an attack on Britannia, charging Camden with inaccuracy and plagiarism.

The degree of Burghley's subsequent influence on the work is unclear: Camden only specifically mentions John Fortescue of Salden, Elizabeth's last Chancellor of the Exchequer, and Henry Cuffe, Robert Devereux, 2nd Earl of Essex's secretary, as sources.

Hugh Trevor-Roper said about them: "It is thanks to Camden that we ascribe to Queen Elizabeth a consistent policy of via media rather than an inconsequent series of unresolved conflicts and paralysed indecisions.

In 2023 enhanced imaging technology using transmitted light made the hidden passages readable, revealing major insights, and confirming that the Annales were deliberately rewritten to depict Elizabeth's reign in a way favourable to her successor.

Pope Pius V was reported to have excommunicated Elizabeth due to "secret plots"; this originally had been the more inflammatory "spiritual warfare", and had been toned down.

[9] Camden's Remaines of a Greater Worke, Concerning Britaine was a collection of themed historical essays, conceived as a more popular companion to Britannia.

[12] In 1600 Camden published, anonymously, Reges, reginae, nobiles et alii in ecclesia collegiata B. Petri Westmonasterii sepulti, a guidebook to the many tomb monuments and epitaphs of Westminster Abbey.

Although slight, this was a highly innovative work, predating John Weever's Ancient Funerall Monuments by over thirty years.

Among Camden's other works were the Institutio Graecae grammatices compendiaria in usum regiae scholae Westmonasteriensis (1595), a Greek grammar which remained a standard school textbook for over a century; Actio in Henricum Garnetum, Societatis Jesuiticae in Anglia superiorem (1607), a Latin translation of the trial of the Gunpowder Plotters, aimed at an international readership; an unpublished essay on printing;[13] and a number of Latin poems.

[15] He died at Chislehurst on 9 November 1623, and was buried at Westminster Abbey, where his monument, incorporating a demi-figure of Camden holding a copy of the Britannia, can still be seen in the south transept ("Poets' Corner").

[15] His circle of friends and acquaintances included Lord Burghley, Fulke Greville, Philip Sidney, Edmund Spenser, John Stow, John Dee, Jacques de Thou and Ben Jonson, who was Camden's student at Westminster and who dedicated an early edition of Every Man in His Humour to him.

[3][18] In an address given in 1986, marking the original publication's 400th anniversary, George Boon commented that the work "still fundamentally colours the way in which we, as antiquaries, look at our country".

[19] Hitherto hidden censored passages in the Annales which became readable in 2023 may significantly change modern interpretations of Queen Elizabeth's reign.