On the face of it, very little.
But all involve letters - the theme of an exhibition which opens on Monday to mark the Archives and Records Association of New Zealand's annual national archives week.
"City of Letters" is a collaborative exhibition featuring selected letters and personal archives about people and their lives which will run at Archives New Zealand's Dunedin office until May 29.
Its contents have come from Dunedin archival institutions the University of Otago Hocken Collections, Presbyterian Archives Research Centre, Dunedin City Council archives, Dunedin Public Libraries, Otago Settlers Museum, and Archives New Zealand.
Lois Robertson, from Archives New Zealand, this week said each institution had been asked to contribute items of general interest which might or might not have been exhibited before.
The result was a mix of "fascinating" personal letters, including divorce correspondence from a Department for Courts file showing what remained at the end of a loving relationship, and a touching letter from a husband to his wife on the eve of a fatal duel, she said.
Presbyterian Archives was contributing letters, photographs, documents, books and a filmed interview from Lorraine Saunders, a missionary who trained as a deaconess (a full-time church worker) at the Presbyterian Women's Training Institute in Dunedin in the 1930s and worked in the northwestern Indian province of Punjab from 1935 until her retirement in the 1970s.
This was the first time the material had been exhibited to the general public, although a presentation about her work was given for church members last year to celebrate the centenary of the church's entry in Punjab, director of archives Yvonne Wilkie said.
"It is interesting to read these letters . . . which were her link with home for all those years."
Miss Saunders, who now lives in Christchurch, will celebrate her 100th birthday this month.
Ms Wilkie said Miss Saunders knew about the exhibition, but it was not known whether she would be well enough to attend.
The social and historical significance of letters, and tips on their preservation, was the theme for this year's archives week, Ms Robertson said.
In Dunedin, a series of lunchtime seminars would be held at the Hocken Collection's seminar room, Anzac Ave, in addition to the exhibition.
The speakers include Dr Angela Wanhalla from the University of Otago history department talking about her research into interracial marriages in colonial New Zealand, Dunedin writer Philip Temple talking about the letters of wartime German writer Maria Blumenthal and Hocken Collections and independent historian Dr Ali Clarke discussing letters about childbirth in 19th-century New Zealand.
