After sitting in a desk drawer for almost 20 years, a large cache of poetry by the British author Patrick O’Brian has been discovered, with the majority unknown even to his own family.

More than 100 poems, which will be collected and published as The Uncertain Land and Other Poems next March, were discovered this year when trustees for the O’Brian estate handed over a manila folder containing the poems. They had been written between the early 1940s to the late 1970s.

His publisher, HarperCollins, and his surviving family had not known that the author, best known for his long-running Aubrey-Maturin series of maritime novels that began with Master and Commander, was such a prolific poet.

O’Brian’s stepson, Count Nikolai Tolstoy, said that he had inherited about 20 poems by O’Brian after the author’s death in 2000, and knew there had been others from the author’s diaries and those of his mother, O’Brian’s second wife, Mary Tolstoy O’Brian. However, he had not seen most of the poems until HarperCollins approached him this year.

“Not many people realise Patrick was keen to be a poet,” said Tolstoy. “He’d be very pleased they’re being published, because he was keen to be seen as a poet as well as an author. He wanted to be a poet from a very young age. He was a meticulous writer, one who enjoyed writing short stories, and I think encapsulating his thoughts in a small compass appealed to him. In her diaries, my mother mentions reading the poems and liking them very much, which encouraged him. But there was no attempt, to the best of my knowledge, to collect them.”

Tolstoy said that how the poems had been collected was “rather a mystery” to him. “It covers several decades,” he said. “If he’d been handing it over bit by bit to his publishers, there would be some record of it, but there isn’t. And I don’t think he would have kept them all in one place – he used to lose things all the time. It is rather mysterious.”

Starting from the early 1940s, when O’Brian worked as an ambulance driver during the blitz, and ending in the late 1970s, by which time O’Brian was a bestselling author, the poems cover an enormous range of topics. From his amusing ditties composed for his colleagues in the ambulance service, O’Brian’s focus shifts to the countryside of Wales, where he moved after the second world war, then to France, where he lived most of his life, finally ending with sombre reflections on ageing and death.

HarperCollins called the discovery a complete surprise. “It is always exciting for a publisher when you hear from the family to say there is newly discovered work,” said Chris Smith, who edited the collection. “This is one of those cliched cases where the work wasrally lying in a drawer for 18 years. Patrick had always been interested in publishing his poetry, and we know he had a conversation with his agent in the 1970s about collecting some, but nothing came of it.”

Although O’Brian guarded his privacy – he was famously cool with reporters fishing for snippets of personal detail and many of his fans were upset when elements of his early personal life were revealed in a 1999 exposé – Smith said the poems were surprisingly autobiographical.

“He seems very preoccupied with ageing – and giving up smoking, there is more than one about giving up the dreaded nicotine,” Smith said. “In some, you can tell he was having trouble with writer’s block and had turned to poetry; in those, there is a real sense of his frustration. He also had a particular fascination with the natural world and wildlife, and many poems focus on the birds and wildlife in the mountains of Wales, and also the landscape in Collioure, where he lived for 50 years. Some are mundane – there is one where he rails against noisy neighbours, something we can all relate to – some are humorous, some are empathetic. But in all of them, you get a real sense of Patrick and all the different facets of his personality.”

“Clearly, in the back of his mind, there would be a collection one day. But for most of his life, he would have been focusing on the Aubrey-Maturin books, as he would have been under contract. But his diaries show that even the sale of a single poem gave him great joy – so it is nice to be able to reveal so many to his readers.”

Farewell my sin I have enjoyed you

Farewell, my sin, I have enjoyed you

Food, drink and women:

there are chains.

Possessions, too.

Why add a strong, insistent, masterful

and new?

Smoke

good mornings’ gate

forerunner, end and crown of meals

or hunger’s stay

calm adjutant of peace and talk

first sign of manhood: in old age

a last delight.

Oh yes. All these and more.

No doubt the helot’s very gay, though bound.

But over all

the principall.

Must smoke. an order Diktat ukase must

I do not like imperatives.

Besides

I throw

the arc of shooting stars, and hiss

it’s gone. Farewell

Farewell, my sin

Goodbye

The Wine-Dark Sea

The ‘wine-dark sea’ a commonplace?

Poetic argot’s hollow ring?

It is not so, I know, to me

who saw last night the purple sea

the even, gently-swelling sea

unbroken, smooth and menacing.

The purple with an edge of blue,

And reddish in the after-glow

the spindrift floating on the waves:

The foaming, dark and rasping wine

they trod in vats some months ago –

These were the same. But then the moon

rose to the edge and spoilt the sea’s

wine-dark dove’s bosom: over these

the nascent stars; Aldebaran

and, half unseen, the Pleiades.