Leiden university was home to the philosophers
Rene Descartes and
Baruch Spinoza for several years. During this period, it had a reasonably liberal and tolerant attitude to those philosophers who would otherwise have gotten into trouble for their opinions concerning
God.
Nowadays, it is a little more traditional...
One other famous previous student is the fictional character Lemuel Gulliver, 'author' of Gulliver's Travels.