Sweet Polly Oliver is an English

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 folk song

Folk music

Folk music is an English term encompassing both traditional folk music and contemporary folk music. The term originated in the 19th century. Traditional folk music has been defined in several ways: as music transmitted by mouth, as music of the lower classes, and as music with unknown composers....

 (Roud

Roud Folk Song Index

The Roud Folk Song Index is a database of 300,000 references to over 21,600 songs that have been collected from oral tradition in the English language from all over the world...

 #367), dating from at least 1840. It is also known as "Pretty Polly Oliver".

It is one of the best known of a number of folk songs describing woman disguising themselves as men

Crossdressing during wartime

Many people have engaged in cross-dressing during wartime under various circumstances and for various motives. This has been especially true of women, whether while serving as a soldier in otherwise all-male armies, while protecting or disguising their identity in dangerous circumstances, or for...

 to join the army.

Thomas Root wrote a symphonic band arrangement of Sweet Polly Oliver. Benjamin Britten

Benjamin Britten

Edward Benjamin Britten, Baron Britten, OM CH was an English composer, conductor, and pianist. He showed talent from an early age, and first came to public attention with the a cappella choral work A Boy Was Born in 1934. With the premiere of his opera Peter Grimes in 1945, he leapt to...

also wrote an arrangement for voice and piano.

As sweet Polly Oliver lay musing in bed,

A sudden strange fancy came into her head.

"Nor father nor mother shall make me false prove,

I'll 'list as a soldier, and follow my love."

So early next morning she softly arose,

And dressed herself up in her dead brother's clothes.

She cut her hair close, and she stained her face brown,

And went for a soldier to fair London Town.

Then up spoke the sergeant one day at his drill,

"Now who's good for nursing? A captain, he's ill."

"I'm ready," said Polly. To nurse him she's gone,

And finds it's her true love all wasted and wan.

The first week the doctor kept shaking his head,

"No nursing, young fellow, can save him," he said.

But when Polly Oliver had nursed him back to life

He cried, "You have cherished him as if you were his wife".

O then Polly Oliver, she burst into tears

And told the good doctor her hopes and her fears,

And very shortly after, for better or for worse,

The captain took joyfully his pretty soldier nurse.