Hi:

Some time ago, as I was surfing the Internet, I came across names of welgeboren men of Rijnland whom appear in Simon van Leeuwen's Costumen, keuren, ende ordonnantien van het baljuschap ende lande van Rijnland (1667).  In some parts of this work, a few of my late father's ancestors appear.  Out of curiosity, I am wondering where the author obtained first-hand information?  Which registers did my ancestors appear in and are the original records located with the Nationaal archief?  If so, can anyone point me in the right direction?  Specifically, I am looking at the following individuals:

page 74: Pieter Keyser, listed in 1500

page 82: Liclaas Foutien, listed in 1532

pages 92, 94, 96: Leenert Gerritz Meurs, listed in 1616, 1626, 1636, respectively.

Any help would be sincerely appreciated.

Thanks.

No answer to the question, but there is a publication of the historical association of Voorburg "100 jaar Laan van Oostenburg, van landelijk zandpad tot statige laan" in which Leendert Gerritsz van Meurs appears. The transcription can be searched using ctrl + f  Van landelijk zandpad tot statige laan - PDF Free Download (docplayer.nl)

Thanks, Anneke.  That's actually a great find on your part.  I really appreciate it very much.

Steve

The men listed in Costumen van Rijnland by Simon van Leeuwen (and the additional list by Ronald van der Spiegel) are those who served as judges in the Hoge vierschaar (the court) of the baljuwschap Rijnland. 
There are two ways you might be able to find them: first, the nominations or appointments of the men by Hof van Holland.  These start in 1594, inv. 3629-3630 < link > .
Second, by going through the court rolls (dingboeken) of the baljuwschap, where for each court day the judges that were present are mentioned. If I understand Simon van Leeuwen correctly, this is what he did.
They should be found in NA  3.03.08.221 Inventaris van het archief van de Baljuw en Hoge Vierschaar van Rijnland, (1539) 1574-1811, but I think the (saved) records only start in 1725. 
You mentioned Leendert Gerritsz Meurs which I find odd, because he lived in Voorburg, which is in Delfland. Why would he (and there are others as well) be sitting in het Vierschaar of Rijnland? I don't know. 

Regards, Frans