You can use the subject headings listed on the 'Biographies' page of this guide, or try a few of these other heading conventions for works about the rulers in history:
For a family or dynasty: Great Britain--History--Stuarts, 1603-1714
For an individual: Great Britain History James I, 1603-1625
By time period: Great Britain History 1660-1714
If you're not sure, use the 'search in "subject keyword"' option.