The last carol of the cycle, I Saw Three Ships was written for Cambridge Music School in the summer of 1962 under the name Carol for Christmas. It was first performed in 1980 by the Auckland Dorian Choir under the baton of Peter Godfrey.
Now I Joseph was walking* was written in the early 70s while I was teaching at Linwood High School and originally had a percussion accompaniment. The other two were written in 1977 to complete the cycle with texts Welcome Lullaby by Brigitte and Can you see the star? by Fiona (aged 7) in Christchurch.
* The Text was discovered by Rod Harries in the Apocrypha:
Now I Joseph was walking and I walked not I looked up to the air and saw it in amazement
Then looked I up unto the pole of heaven and saw it standing still and the fowls of the air without motion
And of a sudden all things moved on in their courses Gloria in excelsis Deo!
Translations of this text differ widely, however, none has the Latin "Gloria in excelsis Deo".
I assume that Rod added the Latin "Gloria" to help emphasise the fact that Jesus was born as Joseph was having this curious experience.