Simplify the following text for a Grade 11 native English-speaking person.
Original: Johan Anthoniszoon `` Jan '' van Riebeeck ( April 21 , 1619 , Culemborg , Gelderland -- January 18 , 1677 ) was a Dutch colonial administrator and founder of Cape Town .
Simplified: Johan Anthoniszoon `` Jan '' van Riebeeck ( April 21 , 1619 â `` January 18 , 1677 ) was a Dutch colonial administrator and founder of Cape Town .