Brussels Summit

The Brussels Summit is a quindecennial summit meeting of the deputy leaders of the three member states of the Hanoverian Union, namely the United Kingdom, the Netherlands, and Luxembourg. Held at the Royal Palace of Brussels, which also serves as the official residence of the President of the Hanoverian Union, the summit meetings are normally held to discuss and subsequently lay out a new agenda for the organisation every fifteen years. Therefore, the summmit meeting itself is mostly considered to be a standard renewal of the organisation's "year", whereby a "year" constitutes a total of fifteen years, during which the deputy leaders from each three member states take turns holding the chairmanship of the organisation for five years each.

The summit meetings are normally chaired by the President of the Hanoverian Union, whom is always the reigning monarch of all three countries. For instance, King Frederick, as the organisation's first and founding president, chaired the organisation' first Brussels Summit meeting in 1946, followed by a second, a third, and a fourth, all three of which were chaired by King Charles III and I as the reigning monarch at the time. The most recent and the sixth Brussels Summit meeting took place on December 6th 2021, and was chaired by Queen Alexandra, whom assumed the presidency of the organisation following her father's abdication in 2017, the latter having chaired the fifth summit meeting in 2006.

Given the trinational nature of the summit meetings, an agenda that was agreed upon and implemented in each summit meeting is formally known as a "Trinational Plan", with the current version being the "Sixth Trinational Plan", which was implemented at the Sixth Brussels Summit in 2021.