Beginning with the death of Marcus Aurelius and the accession of the administratively incompetent megalomaniac Commodus, Goldsworthy seeks to explain the collapse of the Roman empire not, as it is sometimes seen, as a phenomenon created almost exclusively by external pressures but as stemming largely from a cumulative failure of leadership.

The over-reliance of insecure emperors upon the army, the tendency to reward loyalty above merit, the growth of bureaucracy as an end in itself, and the decline in revenues caused by buying off enemies with territory, all combined to hollow out the state. In consequence, its collapse, though slow in coming on account of the sheer size of the institution, was remarkably swift when it finally arrived.

This is not to deny the part played by the barbarian invasions. Indeed, Goldsworthy suggests that the reason why the eastern empire survived longer than its western counterpart was that the incursions it faced were less widespread. The Bosporus presented a significant barrier to invaders, and while the Persians posed a formidable challenge, it is arguably easier to face one large adversary that a series of smaller enemies.

The eastern empire did not lose as much territory and revenue. Thus it was able to maintain a large standing army, while in the west the army which looked good on paper was consistently under-manned. Nevertheless, the east suffered from a similar sclerosis to the west. It lingered on after the collapse of its sister, gradually diminishing in size, a venerable and impressive institution but no longer a super-power.

Goldsworthy's narrative is clear, comprehensive and, given the speed with which emperors rose and fell in the declining years, remarkably easy to follow. It offers the reader a satisfyingly coherent over-view of one of the most significant cultural earthquakes in human history.

The Illusion Of Security

Set in the nineteen sixties, Exposure is the story of Simon, a civil servant in the Admiralty accused of espionage, and the ruinous consequences this has for his wife and three children. Like other books by Helen Dunmore, the focus is on the brutality of ideology and the way that ordinary people are crushed within the political machine.

At the centre of the story is Simon's wife, Lily, a Jew who, as a girl, escaped the horrors of Nazi Germany only to be unwittingly ensnared in the machinations of communist infiltration within British society. As the pressure mounts on Simon and Lily and on the children they so badly want to protect, the couple struggle, each in their own way, to retain their humanity.

It is not an easy read. Compassion is always on the brink of being overcome by cruelty. Yet Helen Dunmore's characters manage to triumph over a seemingly implacable enemy through stubborn resilience and an instinctive understanding of what is most important in their lives. They have to contend with mean-spiritedness from some of those around them but they are also buoyed up by the quiet everyday decency of ordinary people.

This is a novel about illusions - the obscene ideal of a master race, the inhuman belief in the superiority of historical materialism over individual human lives and, above all the illusion of security, that most fragile of human possessions that is so easy to lose and so terribly difficult to regain.

A Paean To Self-Improvement

Alma Whittaker, born in 1800 in Philadelphia to a hugely wealthy plant importer and supplier of herbal medicines, is a highly-intelligent woman who has the misfortune to be physically unattractive to men. Materially affluent but emotionally impoverished, she becomes a botanist specialising in the miniature world of mosses.

When she meets an eccentric illustrator of orchids she falls hopelessly in love and quickly accepts his proposal of marriage but their union is never consummated and they split up. He travels to Tahiti where he dies prematurely. Later, in an attempt to understand his enigmatic personality, she follows in his footsteps.

After an epiphany in Tahiti she begins to develop a theory of evolution but declines to publish her work because she finds herself unable to explain the phenomenon of altruism. Eventually she sees very similar ideas propounded by Darwin to universal acclaim.

The Signature Of All Things is an intelligent, original and provocative piece of historical fiction. Full of colour, underscored by a gentle but unsparing humour, it is an examination of our relationships to the natural world and to each other, as well a paean to self-improvement and scholarship.

There is so much about this novel that is satisfying - the strongly-evoked characters, the confident storytelling voice, the compelling evocation of intellectual excitement, the brave and powerful depiction of female sexual longing, the unflinching examination of the assumptions and misunderstandings that underpin so many romantic relationships.

But, and this is a big but, it all goes on far too long for me. Things that could have been said once are said three times, characters who are meant to be endearing become irritatingly over-indulged. There is an organic proliferation to the text that is no doubt entirely in keeping with the spirit of the book but it did make me wish the editor had done some judicious weeding.

A Compelling Story Of Endurance

A nineteenth century whaling expedition to the Arctic - among the crew, a disgraced Irish surgeon, a captain intent on insurance fraud and a serial killer. That makes it sound rather more commercially-focused than it really is. Instead, the focus is on the pithily -drawn characters who positively leap off the pages, and the powerful evocation of the Arctic setting in which the crew eventually find themselves stranded.

McGuire's storytelling focuses on essentials - the struggle for survival, the need for identity and the desire for a position in the world. The writing is often strikingly poetic, the world, and the men who inhabit it, frequently brutal, the challenges they face, elemental.

It all adds up to a compelling story of endurance, carefully researched, skilfully crafted, and powerfully told. At times the world that Ian McGuire creates seemed more real and solid to me than that one that lay beyond the covers of the book. Extremely enjoyable with a satisfying, if ever so slightly hurried, ending.

A Portrait Of Middle-Class Life

Three sisters, their brother and his new wife, along with assorted children and teenagers, spend a summer holiday in a house in the country that used to belong to their grandparents where they indulge their insecurities, engage in flirtations, misunderstand each other, wilfully or otherwise, and rehearse old grievances. There is also an extended flashback to the breakdown of their parents' marriage forty years earlier, an event that had a profound impact upon them all.

It's a beautifully observed study of a particular strata of modern English life - liberal, self-indulgent, faintly apologetic - and the portrait is painstakingly built up, detail by detail. I can see why some critics have described Tessa Hadley as one of England's finest novelists.

I was reminded in places of Elizabeth Jane Howard. Like Howard, Hadley distributes the perspective equally among the characters, young and old; like Howard, she has a tendency to summarise dialogue rather than reproduce it faithfully. - something that I found rather irritating; and like Howard, Hadley's sensibility is so very English and so middle-class.

My problem with it, however, is that there is absolutely no story. I don't necessarily want a driving plot every time I read a novel but I do like to have some sense of momentum. Otherwise I find it simply too much like hard work; and that is how I felt about this: the characters and their world are exquisitely drawn but the whole thing is so terribly dull.

The story of a Mormon couple living in Merseyside failing to cope with the death of one of their children, A Song For Issy Bradley is a deeply moving portrait of a family in rapid disintegration which also manages to be very funny.

Claire was a convert to Mormonism. She joined because she fell in love with Ian, now Bishop Bradley. Her religion has always been more of an accommodation than anything else and she has tended to ignore those parts of the doctrine that she inwardly baulked it. Now, the death of her daughter Issy has pulled the rug away from beneath her comfortable self-deception. Everything about the religious community in which she has embedded herself, seems irksome and pointless.

I didn't know anything about Mormonism but I do now and, as with all religions, what appears perfectly normal to the initiate seems very weird indeed to the outsider. Carys Bray, who grew up in a Mormon family, brilliantly manipulates the disjuncture between the interior space of a deeply religious family and the uncomprehendingly secular wider world, much of which is seen through the eyes of the dead girl's siblings who have been brought up on tales of miracles and divine intervention but are now confronted with the mundane reality of bereavement.

This is one of those novels that opens a window into a hidden world and, in doing so, simultaneously highlights the strangeness and the sameness of all human behaviour. Sometimes harrowing, sometimes laugh-out-loud funny, this is a wonderful read.

A Post-Apocalyptic Nightmare I Didn't Want To Wake Up From

The premise of this post-apocalyptic thriller makes it sound like a real piece of pulp fiction. The story is set on a military base that is one of the last outposts of humanity. Most of the rest of the human race have been infected by a parasitic fungus that turns them into flesh-eating zombies known as 'Hungries'. Here on the base they are desperately seeking a cure.

Don't be fooled. The Girl With All The Gifts is much more than a genre thriller. It is an intelligently written, character-based piece of speculative fiction. Seen largely from the point of view of one of the Hungries, a highly-intelligent child who only gradually comes to understand her true nature, it presents the reader with a series of moral dilemmas and avoids offering easy solutions.

It's also compelling reading. I had to regularly stop myself reading so I could get on with the rest of my life. Now that's it's over I wish I could start all over again.