The best general survey is Judith A. Green, The aristocracy of Norman England (1997), while David Crouch, The image of aristocracy in Britain, 1000-1300 (1992), is interesting on the broad cultural context. The key monographs are John le Patourel, The Norman Empire (1976); Peter Clarke, The English nobility under Edward the Confessor (1994); and Robin Fleming, Kings and lords of Conquest England (1991), which should be read after Peter H. Sawyer, '1066-1086: a tenurial revolution' in Domesday Book: a reassessment, edited by Peter H. Sawyer (1986), pages 71-85. Robin Fleming, 'Domesday Book and the tenurial revolution' Anglo-Norman Studies 9 (1987), pages 87-102 is not entirely replaced by her book. In addition, Chris P. Lewis, 'The early earls of Norman England', Anglo-Norman studies, vol. 13 (1991), pages 207-23, has some interesting observations on the titled aristocracy before and after the Conquest. F.M. Stenton, The first century of English feudalism (second edition, 1961), is important for the great feudal honors, a subject upon which Sidney Painter, History of the English feudal barony (1943), still has some value. A.R. Wagner. English genealogy (second edition, 1972), contains some insights on the origins of the feudal baronage.
Basic statistical analysis of the manorial values of the estates of the aristocracy is supplied by W.J. Corbett, 'The development of the duchy of Normandy and the Norman Conquest of England' Cambridge Medieval History, vol. 5, 481-520, supplemented by John J.N. Palmer, 'The wealth of the secular aristocracy in 1086', Anglo-Norman Studies, vol. 22 (2000), pages 279-91. C. Warren Hollister, 'The greater Domesday tenants-in-chief', in Domesday studies, edited by J.C. Holt (1987), provides another calculation for the small group of the greatest Norman magnates. Reginald Lennard, Rural England, 1086-1135: a study of social and agrarian conditions (1959), makes important criticisms of the basis upon which all these calculations tend to be made, and contains acute observations on the position of the Anglo-Norman aristocracy as revealed by Domesday Book.
A number of regional studies of the Anglo-Norman aristocracy have implications for the entire Norman settlement. The more important of these are M. Altschul, A baronial family in medieval England: the Clares, 1217-1314 (1965); L.H. Nelson, The Normans in south Wales, 1071-1171 (1966); W.E. Wightman, The Lacy family in England and Normandy, 1066-1194 (1966); Barbara English, The lords of Holderness, 1086-1260 (1979); W.E. Kapelle, The Norman conquest of the north: the region and its transformation, 1000-1135 (1979); J. Meisel, Barons of the Welsh frontier, 1066-1272 (1981); and Richard P. Abels, 'Sheriffs, lord-seeking and the Norman settlement of the south-east midlands', Anglo-Norman Studies, vol. 19 (1997), pages 19-50.
There are also a number of particularly important articles on individual Domesday lords or lay estates by F.M. Stenton, 'English families and the Norman Conquest, Transactions of the Royal Historical Society, 4th series, vol. 26 (1944), pages 325-34; John F.A. Mason, 'Roger de Montgomery and his sons (1067-1102)', Transactions of the Royal Historical Society, 5th series, vol. 13 (1963), pages 1-28; W.E. Wightman, 'The palatine earldom of William fitz Osbern in Gloucestershire and Worcestershire (1066-1071)', English Historical Review, vol. 77 (1962), pages 6-17; Richard Mortimer, 'The beginnings of the honour of Clare', Anglo-Norman Studies, vol. 3 (1981), pages 119-41; 220-21; and Chris P. Lewis, 'The formation of the honour of Chester, 1066-1100', The earldom of Chester and its charters: a tribute to Geoffrey Barraclough, edited by A.T. Thacker (1991), pages 37-68.
Until recently, the Anglo-Saxon lords were less well served by the literature; but matters have improved somewhat with the publication of Peter Clarke, The English nobility under Edward the Confessor (1994), and especially Ann Williams, The English and the Norman Conquest (1995). There is a lot of material buried in Freeman's History of the Norman Conquest (6 vols. 1877-79); and the analysis of the structure of the Anglo-Saxon aristocracy by F.W. Maitland, Domesday Book and beyond (1897), is still of interest. The Domesday possessions of Earl Harold and his men are thoroughly analysed by Ann Williams, 'Land and power in the eleventh century: the estates of Harold Godwinson', Anglo-Norman Studies, vol. 3 (1981), pages 171-87, and those of another Anglo-Saxon magnate, Brictric son of Algar, in 'A west-country magnate of the eleventh-century: the family, estates and patronage of Beorhtric son of Aelfgar', in Family trees and the roots of politics: the prosopography of Britain and France from the tenth to the twelfth century, edited by K.S.B. Keats-Rohan (1998), pages 41-68.
Apart from the book by Robin Fleming, there are few other serious studies of Anglo-Saxon landed estates. Chris P. Lewis, 'Joining the dots: a methodology for identifying the English in Domesday Book', in Family trees and the roots of politics: the prosopography of Britain and France from the tenth to the twelfth century, edited by K.S.B. Keats-Rohan (1998), pages 69-87, outlines the work which needs to be done to take the study of the Anglo-Saxon aristocracy forward. Finally, on the difficult problem of Anglo-Saxon tenures, Susan Reynolds, 'Bookland, folkland and fiefs' Anglo-Norman Studies, vol. 14 (1992), pages 211-27, and the same author's Fiefs and vassals: the medieval evidence reinterpreted (1994), are the most recent guides.
On the long-debated questions of whether the Conqueror introduced feudal military service and imposed quotas of knights on his tenants-in-chief, see J.H. Round, Feudal England (1895), and John Gillingham, 'The introduction of knight service into England', Anglo-Norman Studies, vol. 4 (1982), pages 53-64; 181-87. The related, and equally vexed question, of feudalism and the Norman Conquest has generated a the massive literature, recently reviewed by Susan Reynolds, Fiefs and vassals: the medieval evidence reinterpreted (1994). A briefer examination of the same problems from a different point of view will be found in Stephen Morillo, Warfare under the Anglo-Norman kings (1994).
Finally, R.H.C. Davis, The medieval warhorse: origin, development and redevelopment (1989), is an intelligent sketch of its topic, and Ann Hyland, Medieval warhorses (1994), a more thorough examination.