In this era of attention deficit syndrome, with addiction to mobile devices and social media doing strange things to the brain, it is surprising that so many publishers of non-fiction and fiction persist in putting their faith in thick tomes that take weeks to digest. Surely, the internet generation – and the rest of us – would relish more books that are short but stimulating that we can consume in one or two sittings?

That is precisely what Allen and Lane have attempted with their Penguin Monarchs series penned by leading historians. The Elizabeth I volume by Helen Castor that was published earlier this year is the first I’ve tackled. It is a stylish and stimulating account of the reign of Gloriana, focused on explaining Elizabeth through the prism of her insecurity.

Insecurity is not the word most commonly associated with Elizabeth I. The popular image is of a warrior queen, someone politically savvy and confident of her abilities, who outplayed men and was always ruthless when she needed to be. There were moments of doubt, and flashes of anger certainly, but Bess was strength personified. That is the Hollywood Elizabeth.

But as Castor explains, insecurity and the manner in which she learned to deal with difficulty explains the arc of Elizabeth’s reign. Early on – in her tussles with her half-sister, Mary – she could at several points have lost her liberty and worse. After Mary I’s death, the young monarch’s grip on power was not strong. Good advisers and guile, along with some luck, guided her through.

But England was a small state with a new and contested religious settlement, facing continental Catholic powerhouses. Plots were manifold, and paranoia justified. They really were out to get her.

Her response? A cleverly done dance around the question of marriage, and then the construction of a facade, an unchanging mask emphasising continuity and duty to the nation.

Even until the end Elizabeth had to be alert, although by then she had seen so much to be unflappable in a crisis. Castor’s account of the fall of former favourite the Earl of Essex is particularly sharp. Elizabeth is portrayed as the savvy woman dealing with an over-excited Earl, when Essex botched his handling of Ireland and rushed into the Queen’s bedchamber. She was unfazed by this interruption, coolly asking him to come back in an hour when she was ready. A ruined Essex was put under house arrest. He rebelled and was executed for treason in February 1601. Two years later Elizabeth I was dead, leaving England in a far better condition than she found it.

Writing short and to the point – as Fleet Street journalists used to attest – is much more difficult than writing long. To write captions or news in brief items for a newspaper such as the Sun or the Mail requires a particular skill, the ability to grab attention, shred the unnecessary and tell a story with economy.

This is not to say that all non-fiction should be short. The best historians can sustain the longer form and find new ways of telling familiar stories that brings fresh perspective.

But there is room too for more of these pocket books. Helen Castor has produced a thought-provoking volume demonstrating how one monarch’s personality helped stabilise the English state. That reign was a boon. It created the conditions in which England’s “middling” class – its merchants, its men of letters – were able to put the nation on a path to it becoming later in the 17th century a powerhouse in its own right.

Elizabeth I – A Study in Insecurity By Helen Castor. Allen Lane. ÂŁ12.99.