I love old English folk songs. Here are some of the ones I like that can be found on youtube. Bear in mind a couple of these versions are not the best around, but its all I can find:
John Barleycorn: probably Saxon in origin, oldest full recorded version is from in 1568
The Cutty Wren: Probably assosiated with the English Peasant's Revolt (1381)
Twa Corbies: its variant The Three Ravens was first recorded in 1611, but this version may well be older.
This one is the Three Ravens version. This is by my favourite Enlgish folk singer, Andrew King.
Lay Bent to the Bonny Broom, The Cruel Sister, Twa Sisters, The Bonny Swans etc.: There are many version of this song. The oldest recorded one dates from 1656. There are 21 English version and many in other north european languages including 125 in Swedish.
Nottamun Town: At least mid 17th C., possibly quite a lot older.
Cold Windy Rainy Night: I don't know how oldthis one is. I think 18th century. This is qutie a multi-cultural rendering of it, using a lot of Indian instruments.
Moving On Song: A English gypsy song that's actually quite recent, mid 20th century. Still, worth listening to.
Have You News Of My Boy Jack: a WW1 poem turned into a song by Andrew King. The poem was written by Kipling after his son was killed. I think its extremely moving. The actual song starts at about 2:20
Greensleeves: there is a poular story that Henry VIII wrote it, but this is not the case. It first appears in records in 1580.
Scarborough Fair: 16th century english riddle song
The Murdered Brother: probably 16th c.
All Around My Hat: 19th century
The Blackmith: 19th century
My Johnny Was a Shoemaker: 19th c.