Contains personal and professional correspondence between Hilaire Belloc and various correspondents. It includes Belloc's correspondence with his son-in-law, Reginald Jebb. Much of the correspondence between Belloc and Jebb concerns the publication of GK's Weekly, for which Belloc and Jebb were both directors. Also included is correspondence between Belloc and several members of his immediate family including his children Louis, Eleanor, Elizabeth, and Hilary, as well as his grandson, Philip Jebb ("Pippo"). Belloc's correspondence with the Balfour family is also included in this series.

Also included are photocopies and transcriptions of letters Belloc wrote to his wife, Elodie, while walking from France to Italy in June, 1901. This journey would become the subject of Belloc's Path to Rome. Significant correspondents have been separated out.