About the book (from Wikipedia):
Junius was the pseudonym of a writer who contributed a series of letters to the Public Advertiser, from 21 January 1769 to 21 January 1772. The signature had been already used, apparently by him, in a letter of 21 November 1768. These and numerous other personal letters were not included in his Letters of Junius collection, published in 1772.
There is a marked distinction between the main Letters of Junius, intended for the erudite public, and his miscellaneous letters. The latter deal with a variety of subjects, some of a purely personal nature, such as the alleged injustice of the Viscount Barrington, the secretary at war, to the officials of his department.
The Letters of Junius had a definite objective:
to inform the public of their historical and constitutional rights and liberties as Englishmen;
to highlight where and how the government had infringed upon these rights.
Foremost in his sights was the ministry of Augustus Henry Fitzroy, 3rd Duke of Grafton, a fellow Whig whom Junius viewed as particularly corrupt. Grafton’s administration had been formed in October 1768, when William Pitt the Elder was compelled by ill health to retire from office, and was a reconstruction of his cabinet of July 1766. Junius fought for the return to power of Pitt, who had recovered and was not on good terms with his successors.
Junius’ private correspondence has been preserved, written in his usual disguised handwriting. He communicated with Pitt, with George Grenville, with Wilkes (all opponents of the Duke of Grafton), and also with Henry Sampson Woodfall, printer and part owner of the Public Advertiser.
The letters are of interest on three grounds:
their political significance;
their style; and
the mystery which long surrounded their authorship.
The matter of his letters is considered by some to be invective, though close inspection of his writings reveals a principled man ahead of his time, exposing blatant corruption by the only means available (anonymity) in a country struggling with the idea of freedom of speech.
He began with a general attack on the ministry for their personal immorality. An ill-judged defence of John Manners, Marquess of Granby, the popular Commander-in-Chief of the Forces, by Sir William Draper gave Junius an easy victory over a vulnerable opponent with weak arguments. It was in this short tussle that Junius’ style and wit first developed a reputation and public audience. Junius then realised the potential he had to influence public opinion.
Confidently, Junius then went on to expose the problems at their cause—the ministries of Grafton, Lord North (Grafton’s cousin) and the Duke of Bedford. The core of Junius’ arguments were the arbitrary appointments made by Grafton, presumably to stay in favour with the Duke of Bedford and his party (also known as the Bedfordites or Bloomsbury Gang). Most notable was Col. Henry Lawes Luttrell (later 2nd Earl Carhampton), whom Grafton appointed MP for Middlesex (instead of the duly elected Wilkes), and Richard Rigby, whom Grafton made Paymaster of the Forces. Junius ended with an assault on Lord Chief Justice Mansfield, who Junius argued had set dangerous legal precedents regarding press freedom and political libel from the Wilkes affair.
Junius was highly disappointed not to have influenced King George III in his 19 December 1769 letter. He tried to encourage the King to overcome his resentments towards the petty Wilkes and also to relinquish his trust in corrupt officials. Junius was not a radical anti-royal Whig, as many texts suggest, though he did trouble himself with explaining to the public the real constitutional role of the royal prerogative, and (if engaged correctly) how it benefited the country.
Contrary to some opinions, the practical effect of the letters was highly significant—they made Grafton unpopular enough to end his ministry in January 1770. Junius could only have been disappointed by Grafton’s replacement, Lord North. Junius confessed himself beaten in his private letter to Woodfall of 19 January 1773 for not having achieved his goals. Despite this, Junius’ letters were noticed and talked about for generations afterwards and spread throughout Europe in many languages. His concepts on democratic elections, freedom of the press, legal history and the constitutional rights of individuals are now common-place. Few in history have influenced so many and sparked an interest in such real concepts of liberty.