Rather than Steeleye Span's version, here's a version collected from Phoebe Smith of Woodbridge, Suffolk:

A blacksmith courted me
Nine long months or better
And he who gained my heart
Wrote to me a letter
With his hammer in his hand
Strikes his blows so neat and clever
And if I was with my love
I'd live for ever

Now he talks about going abroad
Fighting for strangers
And you'd better stay at home
Keep from all dangers
For you stay at home with me
My dearest jewel
And you stay at home with me
And don't prove cruel

My true love's gone across the sea
With his cheeks like roses
My true love's gone across the sea
With his cheeks like roses
I'm afraid the broiling sun
Will spoil his beauty
And if I was with my love
I would do love's duty

For it's once I had gold in store
They all seemed to like me
And now I'm low and poor
They all seem to slight me
For there ain't no belief in a man
Nor your own brother
So it's girls, whenever you love
Love one another.

Her tune is a variation of that which became "Monksgate". However "Monksgate" was adapted by Vaughan Williams from the tune sung by Mrs Verrall of Monksgate in Sussex, and evens out some of the changes of rhythm. Don't expect to sing the folk song to "Monksgate" without having to stretch the tune to fit, and even then (although a fine tune) it's a pale shadow of the original traditional version.

Phoebe can be heard singing this on the album "I Once Had a True Love" issued by Topic in 1970. I can't find it in their current catalogue, but it can be heard on Spotify if you have access to that, and is well worth a listen.