The ceremony takes place in Wijtschate, which is part of Mesen (or Messines, as it was known during the First World War). While the British Queen (91) has become too old, it's her grandson coming now.
Catherine "Kate" Middleton was expected to come as well, but she will stay in Britain - despite the fact that it is believed she had nothing major on her agenda. It happens more often that both split up for official ceremonies; Kate is expected to stay with the children George and Charlotte.
Williams will be received by Princess Astrid in Mesen, as King Filip and Queen Mathilde had a full agenda. Filip is attending a 'Marathonradio' event by the VRT's youth radio channel MNM to support pupils in their exams, while Mathilde is at Tour & Taxis in Brussels to promote Sustainable Development Goals for the United Nations.