The seed corn for this database was published in 1992 as a GEDCOM by
Denis R. Reid  and available from
 ftp://www.dcs.hull.ac.uk/public/genealogy/royals92.ged.Z
 ftp://ftp.cac.psu.edu/pub/genealogy/roots-l/genealog/roya92a0[1-9]
and this has been made Web browsable:
 http://ftp.cac.psu.edu/~saw/royal/royalgen.html
and also made Web browsable by Birger Wathne via
 http://www.vest.sdata.no/cgi-bin/ll-gw/BASE=royal92/INDEX=I1?LookupInternal
 (now no longer available)

Another Royal GEDCOM can be found in the FHS package, available as:
 ftp://ftp.cac.psu.edu/pub/genealogy/programs/fhs_b[12].zip

This database has been re-validated from sources and expanded from 3000 to
over 30000 records by my own research. It is a quite different dataset now.

The research bibliography includes:

For details of the Lineages of world Royal Families and overall structure:
 "Dynasties of the World" by John E. Morby, Oxford University Press, 1989.
 republished as
 "The Wordsworth Handbook of Kings & Queens", Wordsworth 1994.

Handbooks useful for navigation:

 "Larousse Pocket Guide to Kings & Queens of Britain and Europe", Larousse,
  1995, eds M. Lee & M. Kelly.

 "Great Dynasties" 1980, Mayflower Books, translation of
 "Grandi Dinastie" 1979, Arnoldo Mondadori (Italian)

For the basic British Royal Lineage with modern data
 "The Royal Line of Sucession - The British Monarchy from Cerdic AD534 to
 Queen Elizabeth" by Patrick W. Montague-Smith (Late Editor, Debrett's Peerage)
 Pitkin Pictorials, 1986.

and also
 "Kings and Queens of Great Britain" by Anne Taut‚. Hamish Hamilton, Penguin 
  1990. (a large wallchart)

 "Lines of Sucession, Heraldy of the Royal Families of Europe"
 by Jiri Louda and Michael Maclagan. MacDonald 1981 & Little Brown 1999.

For depth on British Royalty:
 "Britain's Royal Families, The Complete Genealogy" by Alison Weir,
 Pimlico, 1996.

 "British Monarchs" by Mike Ashley, 1998, Robinson Publishing.

 "Queen Victoria's Descendants" by Marlene A. Eilers, 2nd Ed 1997,
  Rosval Royal Books.

  "Europaische Stammtafeln. Stammtafelf zur Geschichte de Europaischen Staaten"
 by von Frank Baron Freytag von Loringhoven. 1964.
 Bund III. Includes Die Konige von Grossbritannien.  (In German)
 Bund I, II and IV show many other Royal lines.
 "Europaische Stammtafeln Neue Folge" by Detlev Schwennicke
 Bands 1.1 -> XIX,  1998.

For breadth of coverage, but beware of errors (there are a lot of them!)
 "The Royal Families of England Scotland and Wales - With pedigrees of Royal
 descents in illustration." by Sir Bernard Burke, Harrison, 1876.

 "The English and Norman Conquest" by Ann Williams, The Boydell Press, 1995.

 "King Alfred The Great" by Alfred P. Smyth, Oxford University Press, 1995.

For details of Lancastrian and York Royal families and the families of Clarence-
Mortimer, Beaufort, Holland, Stafford and Bourchier and Neville. Correcting
Burkes' Errors.
 "Lancaster and York - A century of English History (AD 1399 - 1485)" by
 Sir James H. Ramsey, Oxford University Press, 1892. (2 Vols)

For details of the Fitzalan family and the Dukes of Arundel
 "Thomas Arundel - A study of Church Life in the Reign of Richard II" by 
   Margaret Aston, Oxford University Press, 1967.

For detail on the de Montford's, de Clare's, the house of Savoyard and the links
to the Welsh and Scottish lines
 "Edward Plantagenet (Edward I) The English Justinian or The Making of the
 Common Law" by Edward Jenks, Putnam's, 1902.

The links with the house of Savoyard
 "Edward I" by L.F. Salzman, Constable, 1968

The house of de Valois
 "Genesis of Lancaster or The Three Reigns of Edward II, Edward III, Richard II
 1307-1399" by James Ramsay, Oxford, 1913. "The Scholars History of England,
 Volume V.

The links between de Valois, the Low Countries, Burgundy and England:
 "England and the Low Countries in the Middle Ages", edited by
 C. Barron & N. Saul, Allan Sutton Publishing, 1995.
 
Details of the early ancestors of the house of Guelph:
 "A Genealogical and Heraldic Dictionary of the Peerage and Baronetage of the
 British Empire" by Sir Bernard Burke, 18th Edition, 1856.

 "The Complete Peerage or a history of the house of  Lords and all its members
 from the earliest times" by G.E. Cokayne revised by G.H. White, 1953.
All volumes have been referenced, but particular mention can be made of:
The siblings of William the Conqueror, and 
 details of the de la Poles, Dukes of Suffolk: Volume XII.
The bastards of Henry I, ibid Volume XI.
The bastards of Charles II, ibid Volume VI.
The Earls of Pembroke and the Earls of Orkney, ibid Volume X.
The Earls of Thomond, ibid Volume XII pt 1.
The Earls of Huntingdon, ibid Volume VI.
The Dukes of Norfolk, ibid Volume IX.
The Earls of Oxford, ibid Volume X.
The Dukes of York, ibid Volume XII pt 2.

For details of the de Valence line
 "Aymer de Valence, Earl of Pembroke 1307-1324. Baronial Politics in the Reign
 of Edward II" by J.R.S. Phillips, 1972.

For details of the links between Eleanor of Castile and other lines:
 "The Court and Household of Eleanor of Castile in 1290. An edition of the
 British Library Additional Manuscript 35294 with introduction and Notes"
 by John Carmi Parsons, 1977.
 
For details of modern desendant of James I, Prussian royals 
  and general Peerage details:
 "Burke's genealogical and heraldic history of the Peerage Baronetage and
  Knightage Privy Council & order of precedence" 99th Edition, 1949 and
  102nd Edition, 1959.

For details of the Counts of Aumale as decended from the Dukes of Normandy:
 "The Lords of Holderness 1086-1260. A Study in Feudal Society" by
 Barbara English, Hull University Press, 1991.

For details of the Kings of Castile and Leon:
 "The Learned King. The Reign of Alfonso X of Castile" by Joseph F. O'Callaghan,
 University of Pennsylvania Press, 1993.

For details of the Angevin Kings:
 "King John" by Ralph V. Turner, Longman, 1994.

For details of Piers Gaveston:
 "Piers Gaveston Earl of Cornwall 1307-1312. Politics and Patronage in the
 Reign of Edward II" by J.S. Hamilton. Wayne State University Press, 1988.

Links between the Scandanavian Houses:
 "Medieval Scandinavia. From conversion to reformation circa 800-1500" 
 by Birgit & Peter Sawyer. University of Minnesota Press, 1993.

 "Nachkommen Gorms des Alten" by S. Otto Brenner, extracts provided by
 Gary K. Jacobson 

Further details on the Earls of Orkney:
 "Orkneyinga Saga. The History of the Earls of Orkney" translation by
 Herman Palsson & Paul Edwards. Penguin 1981.

For Links between the central European Houses:
 "Lithuania Ascending. A Pagan empire within east-central Europe 1295-1345"
 by S.C. Rowell. Cambridge University Press, 1994.

The last Plantagenet:
 "The Lisle Letters. An Abridgement" by Muriel St. Clare Byrne & Bridget Boland.
 The University of Chicago Press, 1983.

"The Courtiers of Henry VIII" by David Mathew. Eyre & Spottiswood, 1970.

Early Kings of Kent, Wessex, Bernicia, Northumbria, East-Anglia, Essex, Deira:
 "Kings & Queens of Britain" by David Williamson (co-editor Bedrett's).
 The Promotional Reprint Company, 1991. Originally Webb & Bower.

The Carolingans and Franks:
 "The Frankish Kingsdoms under the Carolingians 751-987" by Rosamond McKitterick.
 Longman 1983.

Medieval France:
 "Charles the Bald" by Janet L. Nelson. Longmans 1992.

 "The Angevin Legacy and the Hundred Years War 1250-1340" by Malcolm Vale.
 Blackwell 1990.

 "A History of France, 1460-1560 The emergence of a Nation State" by
 David Potter, New Studies in Medieval History, Macmillan, 1995.

Modern data:
 "HRH The Princess of Wales" Ladybird Books, 1982.

For the Kings of Ireland:
 "A New History of Ireland" Volume IX Maps, Genealogies, Lists. edited by
 Moody, Martin, Byrne. Oxford University Press, 1984.

 "Eve of Leinster and Radnailt of Dublin" a usenet posting by Stewart Baldwin
  
 16 Aug 1996

 "The Geraldines. An experiment in Irish Government 1169-1601" by
 Brian FitzGerald. Staples Press, 1951.

 "History of the O'Briens from Brian Boroimhe" by Hon. Donough O'Brien.
 Batsford, 1949.

For Crusader States:
 "Saladin and the Fall of the Kingdom of Jerusalem"  by Stanley Lane-Poole.
 Khayats, Beirut, 1964 (Reprint).

 "The Age of the Crusades. The Near East from the eleventh century to 1517"
 by P.M. Holt. Longmans, 1986.

Scotland:
 "The Foundations of Scotland" by Agnes Mure Mackenzie, Oliver & Boyd, 1937.

 "The Stewart Kingdom of Scotland 1371-1603" by Caroline Bingham, Weidenfeld &
 Nicholson, 1974.

For Medieval Iberia:
 "The Medieval Crown of Aragon, a Short History" by T.N. Bisson, 1991.
  (Data extracted by Tom Camfield )

 "The History of Medieval Spain" by Joseph F. O'Callaghan. Cornell University 
 Press, 1975.

 "The Reconquest of Spain" by Derek W. Lomax. Longman, 1978.

 "The Worlds of Alfonso the Learned & James the Conqueror. Intellect & Force
 in the Middle Ages" ed Robert I. Burns. Princeton University Press, 1985.

 Kings of Iberia by Paul Theroff. Net Posting 03/05/94, via Rik Vigeland
   see also
  

 Burke's Royal Families of the World, 1977. Data extracted by John Macleod
 of London <101621.2060@compuserve.com>

For Arabic/Iberian Links:

 "Muslim Spain" by Anwar G. Cheine. University of Minnesota Press,1974.

 "Arab Blood Royal" by Forrest E. Barber. "The Augustan", Vol XVIII, No. 4, 
  pp 115-124.

For Islamic Lines:

 "Islamic Surveys 5: The Islamic Dynasties. A chronological and genealogical
 handbook" by Clifford E. Bosworth. Edinburgh Univeristy Press, 1967.

 "The Encylopeadia of Islam" 1927-1998.

For Biblical lines:
 The Bible, Authorized Version. (i.e. James VI version)

For the Dukes of Burgundy:
 The House of Burgundy by Paul Theroff. Net Posting via Rik Vigeland
   see also 
  

 "Les Grands Ducs de Bourgogne" by Joseph Calmette. Albin Michel, 1949. or
 "The Golden Age of Burgundy" by Joseph Calmette translated by Doreen 
  Weightman, Weidenfeld & Nicolson, 1963.

The Medici's:
 "Henri II" by Ivan Cloulas, Fayard, 1985. (In French)

 "Catherine de Medicis" by Ivan Cloulas, Fayard, 1979. (In French)

 "Caterina de'Medici" by Orsola Nemi & Henry Furst, Rusconi, 1980. (In Italian)

 "Catherine De' Medici" by R.J. Knecht, Addison Wesley Longman, 1998

Links to the Governors of Virginia:
 "The Royal Descents of 500 Imigrants" by Gary Boyd Roberts, Genealogical
  Publishing, 1993. (Data extracted by Michael Clark  and
  Ed Chapman  Jan 1995 )

Link to Lady Godiva:
 Netposting by Todd Farmerie  6 Feb 1995 and
 Tom Camfield .

The de Clares:
 "A Baronial Family in Medieval England: The Clares, 1217-1314" by Michael
 Altschul. John Hopkins Press, 1965.

The Spencers:
 "A Short History of Althorp and the Spencer Family" (An early 1950's guide
  to Althorp)

Early Viking details:
  The Prologue of,
 "The Prose Edda" by Snorri Sturluson. Translation by Athur Brodeur.
 The American-Scandinavian Foundation, Volume V, 1929.

 "The Heimskringla (The Stories of the Kings of Norway called the Round of
  the World)" by Snorri Sturlason. Translated by William Morris and
  Eirikir Magnusson. Volume 4. Bernard Quaritch, 1905.

Jacobite descendants:
 "Lady Nithsdale and the Jacobites" by Flora Maxwell Stuart of Traquair
  Traquair House, HMSO, 1995.

Dukes of Norfolk:
 "The Howard Papers: with a biographical pedigree and criticism" by
  H. Kent Staple Causton, 1862.

 Debrett's 1995, extracts provided by Louis Epstein 

 The Cliffords:
  "The House of Clifford from before the Conquest" by Hugh Clifford 
    of Chudleigh, 1987, Phillimore.

 The Kennedy's:
  "Culzean Castle & Country Park" (guidebook), National Trust for Scotland,
   1992.

 The Douglas's (but beware that Hume took liberties with the truth!):
  "David Hume of Godscroft's 'The History of the House of Douglas' "
 edited by David Reid. The Scottish text Society, 1996

 The Cecil's of Burghley:
  "Burghley House" (guidebook), by Lady Victoria Letham, Jon Culverhouse,
   & Dr. Eric Till, English Life Publications, 1989.

 The Sykes of Sledmere:
  "Sledmere House" (guidebook), Sledmere House, Jarrold Publishing, 1988.

 The Dukes of Northumberland:
  "A History of the House of Percy" by Gerald Brenan, Freemantle, 1902.

  "The de la Pole Family of Kingston upon Hull", by A.S. Harvey,
   East Yorkshire Local History Society, 1957.

 The Dukes of Bedford:
  "Woburn and the Russells", by Georgiana Blakiston, Constable, 1980.

  "Woburn Abbey", A Guide Book, Jarrolds, 1995.

 The Dukes of Marlborough:
  "Blenheim Palace", A guide book, Duke of Marlborough, Jarrolds, 1993.

 The Verney Family:
  "Claydon House", A guide book by The National Trust, 1978.

 Miscelaneous Links to English Gentry:
 "Burke's Landed Gentry", 17th Edition, 1952.
 "Debrett's Peerage, Baronetage, Knightage and Companionage" 1972-73.

 "The Paston Family in the fifteenth century" by Colin Richmond, CUP 1990.

 "An Uncommon People, A study of England's Elite" by Paul Bloomfield,
 Hamish Hamilton, 1956.

 Canonised Royalty:
 "A Calendar of Saints. The lives of the Principal Saints of the Christian
  Year" by James Bentley. Orbis Publishing 1986. Republished by Little, Brown
  and Co 1993 & 1994.

 The Family of Earl Derby:
 "The Derby Diaries" edited by John Vincent, The Royal Historical Society, 1994.

 The Agilolfing dynasty of Bavaria and the Kings of Lombardy:
 "Reallexicon der Germanischen Altertumskunde", data extracted by
 Stewart Baldwin 

 Contemporaneous Information obtained from various sources such as BBC Radio
 and TV News, Hello Magazine, Newspapers, and the usenet newsgroups
 alt.talk.royalty and soc.genealogy.medieval and other similar sources.