The collection primarily comprises correspondence received by Martin Gascoigne from his parents Rosalie and Ben Gascoigne, his brother Toss and his sister Hester. This family correspondence covers an important period of the Gascoigne family's lives and careers and was a critical source for Martin Gascoigne's Catalogue Raisonné of Rosalie's work published by the ANU Press in 2019. There is also a small amount of other personal and business correspondence written and received by Martin. The collection includes transcripts of many of the letters written to Martin Gascoigne, with annotations by Martin regarding references to Rosalie Gascoigne's art.