The first modern centenary celebration occurred in 1617

Evidence

The first of all these modern centenary celebrations seems to have been organized in Germany, in Saxony in 1617; the event it was commemorating had taken place a hundred years earlier. — Neil MacGregor, A History of the World in 100 Objects, 1302

Categorization

• corroborated: 2 independent passages support this claim — Neil MacGregor, A History of the World in 100 Objects, 1302