This edition has been a decade in the making and was only possible due to the help and generosity of a wide community of people and institutions. I first began working with Lady Ranelagh’s letters during my doctoral research on the RECIRC project at the University of Galway. While my PhD explored Ranelagh’s reputation and reception, I wanted to have read all her extant correspondence in order to be able to assess this reception properly. It was then that I had to follow a path walked by every scholar interested in Lady Ranelagh, numerous research trips to a wide range of archives, and it was on one of these trips that the idea for this edition began to form. The idea that I compile an edition was then solidified through conversations with Marie-Louise Coolahan and Michelle DiMeo. I am indebted to Marie-Louise and Michelle for their unwavering support and advice ever since. I am extremely grateful to Felicity Maxwell who took the time to help teach me palaeography in the first year of my PhD. I am also in debt to Ruth Connolly who kindly shared with me her translations of Ranelagh’s letters preserved in German in the Hartlib Papers archive. This would have been a much poorer edition without both of their help. As co-editor of the Camden Series, Siobhan Talbott has shown kindness and patience as deadlines for this edition were revised due to the knock on effect of the COVID-19 pandemic, combined with research trips being cancelled due to severe weather disruptions. I am grateful too for her feedback on earlier drafts of the introduction and appendices. So many scholars have been extremely generous with their time, sharing of notes, references, and advice since I started work on this edition including Dan Carey, John Carrigy, Sajed Chowdhury, Danielle Clarke, Mark Empey, Jane Grogan, Wes Hamrick, Michael Hunter, Willy Maley, Naomi McAreavey, Erin McCarthy, Bronagh McShane, Emilie Murphy, Helen Newsome, Carol Pal, Deana Rankin, Ann-Maria Walsh, and Gillian Wright. Colleagues at the University of Galway and, more recently, Maynooth University have supported this edition in many ways and I am grateful to them, especially Philip Mac a’ Ghoill, Deirdre Nic Chárthaigh, Stephen O’Neill, Pat Palmer, Kevin Tracey, and Alan Waldron.

I am grateful to the European Research Council, and the Irish Research Council who through my work on Marie-Louise Coolahan’s RECIRC project and Pat Palmer’s MACMORRIS project funded research for this edition under the European Union's Seventh Framework Programme (FP/2007–2013/ERC Grant Agreement no. 615545) and Irish Research Council 's Laureate awards (Ircia/2019/116). I am also indebted to the repositories that hold Lady Ranelagh’s correspondence for their permission to reproduce transcriptions for this edition. I would like to thank the Governors and Guardians of Armagh Robinson Library for their kind permission to reproduce the correspondence between Lady Ranelagh and Anthony Dopping. I must also acknowledge the kindness of Carol Conlin at Armagh Robinson Library, Oliver House at the Bodleian Library, Lord Egremont at Petworth House, Diane Ladlow at West Sussex Record Office, Simon Johnson at the National Records of Scotland, Chris Rawlings at the British Library, James Towe at Chatsworth House in Derbyshire, Rupert Baker at the Royal Society Library, Jacky Hodgson at Sheffield University Library, Maya Terhune at the Houghton Library, Becky Wright and Lucy Saint Smith at the Library of the Society of Friends, Margaret Baillie at Chester County History Centre, and Neil Johnston at the National Archives. I am also grateful to the staff at the British Library, the Bodleian Library, and the National Library of Ireland.

Finally, I want to thank my friends and family for their support and encouragement throughout this process. My grandfather and grandmother, Paddy and Margaret, supported me in any way they could, listening to me talking about the letters, and even driving me to and from Armagh when I needed to visit the archive there. I am grateful to David Conlon for his hospitality and company during an extended research trip at the Bodleian Library. I am especially thankful to Michael Doyle and Sarah Gorey who, in the year we lived together, constantly came home to notes everywhere, me using the TV as a monitor for checking transcriptions, and then had to listen to me talk about what I had transcribed. However, my greatest debt is to my partner, Kate Doyle. She has had to live with Lady Ranelagh for as long as I have, has heard all about every letter in the edition, and has put up with many a busman’s holiday where I would deviate into an archive, just to ‘check a few things’. Her patience and willingness to combine our first few chances to get away together after the lockdowns with archive trips are a key reason this edition got over the line. This is for her, with thanks and love.