Simplify the following text for a Grade 8 native English-speaking person.
Original: From 1515 to 1523 , the Habsburg government in the Netherlands also had to contend with the Frisian peasant rebellion , led first by Pier Gerlofs Donia and then by his nephew Wijerd Jelckama .
Simplified: In the 16th century the Holy Roman Empire ( HRE ) had to deal with the rebellion of the Frisians lead by Pier Gerlofs Donia and Wijerd Jelckama . This lasted from 1515 until 1523 .