This is the period our project is concentrating on for the time being (note that there is a difference in scale between this graph and the previous one to accommodate the fact that so many more quotations were recorded by the lexicographers for the period after 1500).

The peaks and troughs are less extreme but still noticeable. Do they tell us about variations in the language or about what the lexicographers chose to read and record – or some combination of the two?
 
It seems clear that some of the abrupt rises in the line can be attributed, as before, to the intensive excerpting of one or more individual authors or works. Thus the increase between 1520-1529 and 1530-1539 is substantially contributed to by 5,409 quotations from a single text, Lesclarcissement de la langue francoyse. This was a bilingual French-English dictionary published by John Palsgrave in 1530, and accounts for well over half the total number of OED quotations recorded for that year (7,218). For more on Palsgrave see Stein 1997. The OED's occasional heavy dependence on individual dictionaries and glossaries - some rather than others - is an interesting phenomenon. See further Schäfer 1989.

The next steep rise, between 1580 and 1600, is in large measure due to the OED lexicographers' devoted documentation of Shakespeare's vocabulary over this period (around 33,300 quotations), while that between 1630 and 1660 is probably attributable to extensive excerpting of pamphlets printed during this period of civil unrest.

Shakespeare's vocabulary, and what OED tells us about it, is a rich and complex subject. Schäfer 1980 was the first work properly to explore the implications of the OED's fondness for Shakespeare, and the bard's lexical creativity has been recently discussed again in Crystal 2008; see further our page on OED's quotation collection for the Early Modern English period.

Returning to the graph: note the significant dip in the eighteenth century – why was this? And the steep rise in the nineteenth century (was the language expanding, or were lexicographers and readers more keen on their own contemporary sources? See further our pages on OED1's treatment of the 19th century and OED3's revision of the period 1500-1899).