"I only wish that I was there,'' he wrote, adding that he hoped to be home by next Christmas to enjoy "plenty of fizz, ale and wine."

Sergent Hill didn't live to see Christmas of 1917. He died the following September 22 of wounds.

Hill's letters are part of a Christmas collection held by the State Library of NSW which spans more than 100 years. It ranges from those sent by soldiers in the trenches of France to 40 years worth of Christmas letters sent from Dubbo by Mrs Gwynneth Gleeson.

Now 89, Mrs Gleeson started sending circular letters to her friends while pregnant at 40 with her sixth and last child in December 1964.

"I was pregnant with very bad varicose veins, and Bill my husband said to me, 'You are not going to stand around to find the right cards. Let's do what your cousin does and send a Christmas letter'.''

Like the other 8,000 Christmas letters donated by ordinary Australians, Mrs Gleeson's provide an annual family audit of births, deaths, achievements and losses, a history of the comings and goings of our lives.

In the first year she wrote about her own pregnancy, daughter Jill's love life continuing to ''amuse (and confuse) us all,'' and her husband's appointment as principal of Dubbo High School.

By 2000, daughter Jill had grown up and was acting as typist for her mother: "James plays soccer and tennis and t-ball and Auskick and has lost two front teeth."

Daughter Libby had celebrated a significant birthday, while another daughter Jen had crossed the bridge in a wheelchair.

Two years later, the letters reflected on life after September 11, 2001. "I am still optimistic because I would like to think that my beautiful grandchildren could live in a world free from the threat of war." Mrs Gleeson wrote to friends that she was the same age as her granddaughter Jo when she heard news of the bombing of Darwin, and said she was distressed that Jo's generation was to experience something so similar.

Now about to send the 49th Christmas letter, one now compiled on computer at her direction by daughter Jill, Mrs Gleeson said her friends looked forward to the newsy letters. But she worried that with fewer people sending letters, the art of letterwriting could be fading.

That's a fear shared by Tracy Bradford, the head of manuscripts at the State Library of NSW.

"Pre-Facebook, it was a way of sharing what people got up to,'' she said of the Christmas letters. "You had to wait until Christmas to find out the whole year's worth of news rather than seeing it on a day to day basis.''

Now many people opted to send greetings via text messages and social networks.

"In 50 years time will researchers look back and see a big hole in the record of our society because things now live in the cloud or because we are using portable handheld devices to communicate?'' said Dr Bradford.

While some people may poke fun of Christmas letters, they have provided the Gleesons with a valuable family history, said daughter Libby Gleeson.

"I understand people taking the mickey (out of them ) ... but on the other hand, I personally find them really interesting as a record of family,'" she said.

When she reread them, she was taken back to the moment, whether it was a birth or a death.

"That is quite poignant at times. And that too is a valuable thing, you've got this record of moments of importance."

Reminder from the State Library: Print out your Christmas letters for posterity!