Early in the 19th century, there were some 260,000 of them across Britain’s naval and merchant fleets. People called them Jacks, but they are mostly nameless – or nameless to history. Even on surviving muster lists, seamen’s identities can be hidden behind pseudonyms. Some of these – George Million or Jacob Blackbeard, say – express a degree of wish fulfilment. Others are more whimsical: a Mark Anthony and Julius Caesar could be found on board the Calcutta-bound Tyger in 1757.

To join them was to enter another world, with its own laws (the thirty-six Articles of War, read to them every Sunday, besides whatever strictures a captain thought fit to apply), its own rituals and its own argot. ‘All seemed strange,’ one former ship’s boy recalled of his first days on board, ‘different language and strange expressions of tongue, that I thought myself always asleep, and never properly awake.’

There were, of course, distinctions among them. The lowest of the low were the waisters, comprised of old men, boys and the most inexperienced landsmen, good for nothing but drudgery. Then came the afterguard, consisting of ordinary seamen and more skilled landsmen, who trimmed the after yards and the sails. Above them were the forecastlemen, able seamen who handled the lower ropes and saw to weighing and anchoring. Princes over all of them were the topmen (or Foremast Jacks), who went aloft to bend or reef the sails, even in the highest of seas.

As Stephen Taylor argues in this enthralling new book, it was men like these who, in the great age of sail, made the British Empire possible. He tells the story of Britain’s rise to maritime supremacy in roughly the century from 1750 to 1850, using first-hand accounts of life on the lower decks, official records – ships’ logs, muster rolls, court martials and so on – and other contemporary sources.

Because of the immediacy of these sources, and Taylor’s deft, incisive use of them, it is the men, not the nation, to whom Sons of the Waves belongs. ‘Out of the King’s service they are in general citizens of the world,’ one officer wrote of them. Jacks might have made the British Empire possible, but they were only circumstantially loyal to it.

When their personal discontent became intolerable, they deserted in their tens of thousands. Nelson himself reckoned that 42,000 deserted between 1793 and 1802 alone, a figure Taylor believes may be on the low side. Their skills made them highly prized commodities and they were happy to sail under any flag, towards any compass point. The institution that valued that commodity least was the Royal Navy.

Perhaps the most resented British naval practice in this period was impressment, the seizure of experienced seamen (and, after 1798, almost any suitable man) for service on the waves. Those pressed on land often left behind wives and children, who were condemned to destitution. Taylor highlights the case of Mary Jones, a mother of two, one newborn, who was evicted from her home after her merchant seaman husband was taken. She was hanged in October 1771 – suckling her baby on the gallows, it was said – for stealing a length of cloth. Those pressed at sea might have spent two years sailing to India and back, only to be seized within sight of English shores – and two years’ backpay – for another year or more of service.

The ‘obnoxious discipline of the British navy’, in the words of one 19th-century seaman, was shameful too. It wasn’t just the floggings, which comprised anything from twelve strokes, the typical beating for drunkenness, to three hundred or more for desertion or mutiny. There were also practices such as ‘starting’, which saw officers beating men to their stations. How much violence a crew might experience was solely down to the character of the captain under whom they served.

Then there was pay. By 1797, it had been stagnant for an eye-watering 150 years. It was this, more than anything, that led to the greatest mutiny in British maritime history, when eleven ships of the Channel Fleet, in the middle of a war with France, revolted at Spithead (the men also sent ashore ten captains and over a hundred junior officers they regarded as too malignant to serve under). It was industrial action avant la lettre, audacious and astonishingly brave, and it was successful. The Commons voted through the funds – fully £372,000 – to meet the mutineers’ demands within weeks.

It is Taylor’s handling of episodes like this, alongside sea battles and shipwrecks, that makes Sons of the Waves so compelling. This is maritime history, but it is also social history of the highest order. He gives us too an authentic sense of the emotional hinterland of ordinary seamen. Chaplains routinely despaired at their indifference to the Christian God of dry land. Yet the rules that governed their lives were so far removed from what pertained on shore, wholly subject to the whims of their commanders and the vast, unfathomable caprice of the sea, that they might have been on another planet.

In a sense, they endured extraordinary physical constraints in pursuit of a kind of psychological, almost metaphysical liberty. Taylor reaches for the old Norse term aefintyr – meaning a certain kind of spiritual restlessness, the itch of every horizon – to explain it. But one of his sources, Edinburgh-born seaman John Nicol, summed it up well enough when he wrote, ‘no matter whither, only let me wander’.

If most of these men’s names have seeped into oblivion like so much sea froth, Taylor has brought their experiences back to vivid and exhilarating life: he stitches together the brutality and wonder of their lives with intelligence, judgement and compassion. In whatever afterworld they now find themselves, tens of thousands of long-forgotten souls will surely be giving a ferocious roar of approval.