Wearing a military uniform and a mask over his face, h Queen Maxima her Netherlands she appeared almost unrecognizable on Tuesday at a Dutch armed forces training center near Amsterdam.

54-year-old Maxima took part in two training exercises with members of the Royal Military Police, Dutch media reported. In one of these exercises, the Queen of the Netherlands helped administer first aid to the “injured” in simulated combat conditions, as some participants described it.

The exercises took place at the training center in Harderwijk, about 70 kilometers east of Amsterdam, as part of the voluntary service year, a program aimed at attracting new recruits to the Dutch armed forces.

Queen Maxima’s daughter, 21-year-old Princess Amalia, began military training in September, receiving the rank of non-commissioned officer. At the same time, he is studying Law at the University of Amsterdam.