1. O'Dempsey's Country
2. The Territory of Ancient Offaly
3. The Territory of Ancient Offaly II
4. The Traditions of Clonsast
5. 4th Letter
6. The History of Killeigh
7. O'Molloy's Country of Fear Ceall
8. The Battle of Moylena
9. Index of Ordnances Survey Letters
10. Ordnance Survey Letters for Offaly 1838
11. Eiscir Riada and the Edenderry District
12. Lynally and Rahan
13. Treasure in Ballykillan
14. Killoughy and the Hill of Croghan
15. Croghan Hill
16. Tullamore River, Killurin and Ballintogher
17.  Ballycowan and Sragh Castles
18. Kilbride (Clara), Ballyburley, Killclonfort and Ballycommon
19. Durrow and Geashell - The English Authorities Attacked
20. "A County of Bogs and Morasses"
21. Castles in West Offaly
22. Did A Gallogoly Kill Hugh De Lacy?
23. Clonmacnoise (1)
24. Clonmacnoise (2)
25. Clonmacnoise (3)
26. Clonmacnoise (4)
27. Clonmacnoise (5)
28. Lusmagh - The Plain of Herbs
29. Gallen and Clonony
30. Hugh de Lacy's murder at Durrow in 1186
31. Leamanaghan
32. The Castles of Mac Coughlan's Country
33. The Will of Sir John Coghlan
34. The Boundries of O'Molloy Country of Fear Ceall (1)
35. The Boundries of O'Molloy Country of Fear Ceall (2)
36. Fearcall - (From the Inquisitions). Castlegeshill, 23 Oct., 1612. (8 Jac I.).
37. O'Molloy Chief killed by a beggar
38. Rahan in Ancient Meath
39. Banagher and Cloghan
40. John O'Molloy of Eglish - The Soogan Chief
41. John O'Donovan and T.L. Cooke
42. The Name Banagher
43. The Old Church at Drumcullen
44. Seir Kieran
45. T.L. Cooke - "A Good Rogue and Sound Historian"
46. Offaly Placenames
47. Kilcolman Church
48. Kinnitty
49. Kinnitty Parish
50. Placenames In Fear Ceall and Ballyboy
51. Ballybritt and Leap Castle - A Liar at Leap
52. Rathleen, Killoughey
53. Rahan and Roscore
54. The Extent of Ely O'Carroll
55. The Cantreds of Ely O'Carroll
56. The Genealogy of the O'Carrolls
57. Ely O'Carroll
58. Kilcomon Old Church
59. Dunkerrin District
60. Stories of the Offaly Saints
61. Extent of the Dioceses in King's County
62. Shinrone and District
63. Townland of Litter and Cadamstown
64. Durrow (1)
65. Durrow (2)

The Ordnance Survey Letters for County Offaly, part of a country wide series, are commonly known as O'Donovan's Ordnance Survey Letters, after John O'Donovan, the famous historian.

The Ordnance Survey Letters of 1837-1838 represent the first attempt on a systematic basis to collect material on Offaly's historical and archaeological remains. The pioneering effort of the Ordnance Survey and of its topographical department in particular was not emulated until the publication some 150 years later of the Archaeological Inventory of County Offaly. O'Donovan's Ordnance Survey Letters are in manuscript form in the Royal Irish Academy and were published in a typescript by Fr. Michael Flanagan in 1933.

The Offaly material consists of letters of John O'Donovan and of Thomas O'Conor. O'Conor, a native of Carrickmacross, was assistant to O'Donovan. Both men had spent September, October and November of 1837 in County Westmeath and in late December of 1837 their attentions turned to Offaly, then and until 1920 called King's County. The letters concern local antiquities, place-names, early Irish history and the genealogy of the native families

It should be noted that in the Westmeath letters are one of John O'Donovan's from Tullamore and another from Edenderry. That from Tullamore is dated 1st January 1838 and could properly be in the King's County volume.