Smyth wrote his Lives of the Berkeleys from 1616 to 1640. Partly it was written as an instruction for the new lord Berkeley, George, and partly it must have been written as a labour of love, Smyth being all of the Berkeley High Steward, a lawyer and a scholar.

He wrote the book from four main sources, first the documents in the muniment room at Berkeley castle. Second from the archives of the kings in London, to which he had access as a lawyer. Third from contacts of the extended family including pedigrees they had concocted. Fourth from his personal knowledge of the family from the late 16th century onwards.

The first two of these were used to construct his lives of the dozen or so lords of Berkeley. The scholarship in these accounts is very evident. His knowledge of the extended Berkeley cadet lines up to the 14th century seems mostly to be taken from such sources.

For the cadet lines of the 15th century onwards, his information is little more than the names and has the signs of being constructed from family pedigrees such as are to be found in the Visitations of that time and, later, in Burke's volumes. The cadet lines may be right but there is no evidence.

Finally for the more recent generations we are back on level ground once more as Smyth was in touch with if not all the members of those families, at least with some who could give him their lists of their own families.

What I have done is to put every member of the extended Berkeley family into a database, just over two thousand in all. They are all included. If there was some discrepancy between Smyth and other sources in my possession, I have discussed this in the notes on that person and, if appropriate, altered the genealogy to what looks the more correct. But such corrections to Smyth can be counted on the fingers of one hand.

For the better part, I would cite Smyth as a model of genealogical scholarship as he generally followed the maxim of using contemporary documents. His genealogy of the cadet families is perhaps no more than a tenth part of his volumes, the main purpose being the accounts of the lives and estates of the principal players, the lords of Berkeley.

Here's the genealogy:

• The Berkeley Family by John Smyth, a searchable tree (The seal is that of Thomas V, lord Berkeley (1472-1533) )
• A GEDCOM of the family, without extended biographies - 113 Kbyte
• Same GEDCOM but with extended biographies for a few people - 543 Kbyte
• The source file in Mac Reunion format with additional info for searching - 650 Kbyte
• The old source file from 2003 in PC Generations format with additional info for searching - 626 Kbyte

Obviously I will have made the odd, hopefully minor, error in copying out all this. Please get in touch about any problems.