It was known as a ‘Blighty wound’ – an injury sustained in the trenches of the First World War that was considered serious enough to require treatment back in ‘Blighty’, meaning Britain. Trapped in the horrors of the Western Front, some soldiers yearned for such a wound so long as it was not life-threatening or life-changing. But many returned with injuries so appalling and disfiguring they might have wished they’d been left to die in the mud and havoc.

I thought of these shattered young men as I stood outside Cambridge Military Hospital in Aldershot, one of the three sites I explore in this section (the others being the Royal London Hospital in the East End of London and the sewers beneath the seaside town of Brighton). Each represents an important step change in our knowledge of medicine and health in Britain.

You may think I chose Cambridge Military Hospital because of its pioneering surgical work in fixing broken soldiers. That was indeed my initial assumption and motivation. The Cambridge was one of the specialist hospitals to which the worst cases of physical disfigurement were repatriated during the First World War. Built on a hill, it dominates the surrounding landscape as Britain dominated much of the globe when the hospital admitted its first patients twenty-one years before the turn of the twentieth century. It is a statement of power and greatness, telling the world that nothing but the finest treatment and surroundings will do for men who have served queen and country, and put their lives on the line for Empire.

I felt a particular affinity for the Cambridge, probably because it reflects a tradition that goes back to King Charles II and the Royal Hospital at Chelsea, where I have attended many parades and events as the constituency MP. Before the king commissioned the Chelsea hospital, which opened in 1692, the state did not take responsibility for injured soldiers or those who had fallen on hard times. The magnificent hospital designed and built by Sir Christopher Wren on the banks of the Thames, in what was then open countryside, expressed the gratitude of a nation for its fighting men. (This was in turn inspired by the Hôtel des Invalides, the complex of buildings authorized by Louis XIV and completed in Paris in 1676. Both the Chelsea hospital and Les Invalides still serve as retirement homes for old soldiers.)

Not only does Cambridge Military Hospital catch the eye, but it also harmonizes design and function. Its long spinal corridor provided easy access for busy nurses shuttling between different departments. The wards were high-ceilinged, with large windows admitting plenty of healthy and cheering natural light. For those men returning from the hell of the trenches it must have seemed a haven of organization and optimism. And the work that took place there, under the authority of the plastic surgeon Harold Gillies, was truly astounding. But the story that arose out of Gillies’ work at the Cambridge Hospital was not, in the end, the one I had expected to hear.

It’s a riveting narrative that I shall leave you to discover in the chapter proper but it does serve to illustrate a truism about medicine: that the most innovative medical practice often takes place in the most challenging of environments. In the years of the First World War and after, that was certainly true of Cambridge Military Hospital. And you could make the same case for the Royal London Hospital, in the nineteenth century especially.

While it was not located in a war zone, the Royal London, on the Whitechapel Road, did serve one of the most deprived areas of London, a neighbourhood of squalor and disease where, in the words of the American writer, Jack London, ‘the obscenities and brute vulgarities of life are rampant’. It is no surprise that the doctors who worked there, the students of the medical college and the staff of the nursing school were at the forefront of best practice for over 250 years. Above all, it was a place of humanity, as hospitals should be. If there is one image that for me sums up the spirit of the Royal London, it is that of the ‘Elephant Man’, Joseph Merrick – a man even more hideously disfigured than the worst cases from the Western Front – and Frederick Treves – the eminent physician who looked after him – conversing as equals and friends in Merrick’s basement rooms in the hospital.

Merrick’s board and lodging at the London Hospital was paid for by a concerned public, following an appeal published in The Times. This arrangement echoed the charitable ethos of hospitals in medieval times, when they provided care and accommodation for the poor, the blind and the itinerant, as well as the sick. The London Hospital had opened in the mid-eighteenth century as a ‘voluntary hospital’, independently run and funded by contributions from wealthy individuals and philanthropic organizations. Similar hospitals opened in other parts of London, including Guy’s in Southwark and the Middlesex in the West End, and across the country, from the Royal Infirmary in Edinburgh to Addenbrooke’s in Cambridge. It’s important to make this point because it shows that the principle of providing free healthcare to those who could not afford to pay predates the establishment of the National Health Service in 1948.

In the chapter on the Royal London Hospital I talk about the medical advances that took place there in the nineteenth century – not least in surgery, facilitated by a local supply of fresh corpses for students to practise on. Another crucial development was in the branch of medical science known as epidemiology. This, briefly, is the study of where and how diseases originate in a given population. The doctor credited with its creation is John Snow, whose work in tracing the origins of a cholera outbreak in central London I refer to in the chapter on Brighton’s sewers.

Before Snow demonstrated that cholera was being spread by water contaminated by sewage, it was generally thought that disease was transmitted by ‘miasmas’ or toxic vapours. No one thought to question the basic system of sewage disposal that emptied human waste in open channels directly into London’s streams and rivers, which then emptied themselves into the Thames. John Snow died on 16 June 1858, just a few days before the stench of the Thames at Westminster grew so unbearable in the hot weather that it became known as the ‘Great Stink’.

The Great Stink forced the government not just to hold its nose but to do something about the river of effluent that the Thames had become. Parliament resolved to create a modern sewerage system beneath the rapidly expanding metropolis and the man responsible for the design and implementation of this huge engineering project was the chief engineer at the Metropolitan Board of Works (the forerunner of the London County Council), Joseph Bazalgette.

Bazalgette tends to monopolize the story of sewers in Britain. But in towns and cities throughout the country Victorian engineers of comparable vision began building sewerage systems as part of a wider industrialization that has shaped modern Britain. Brighton was a particularly urgent case. After the arrival of the railway in 1841, the town billed as ‘merry Dr Brighton’ was looking increasingly green around the gills. Day trippers and fun seekers were arriving by the trainload and the basic sewerage systems couldn’t cope. The result was polluted water sources and some of the worst outbreaks of cholera in the country – though you’d hardly have known it from news reports, as the tourist authorities kept a lid on the dire state of Brighton’s public health.

The engineer responsible for the sewers beneath Brighton was John Hawkshaw and he had a hand in many significant infrastructure projects of the Victorian era, from the Severn Railway Tunnel to sections of the London Underground. Like everything the Victorians touched they were built to last and still work. I love the fact that Brighton’s sewers are better built than the flashy Regency squares they underpin.