The administration of the Royal Court is located here, and this too is the setting for most of the official receptions given by the Head of State.
The history of the Royal Palace goes back many centuries. Extensive excavations of the surrounding area (Helgeandsholmen) between 1978 and 1980 revealed traces of very ancient timber structures, dateable to the end of the 10th century.
These finds have been variously interpreted.
These barriers may have been guarded, but the question is whether they had a full garrison of soldiers or just a single watchman.
But of one thing we can be sure: the shipping lane now called Norrström ("North Stream") was of sufficient strategic importance for somebody to put barriers across it a thousand or so years ago.
According to the latest research, this tradition is in all probability correct. The fortress consisted of two parts: the keep had a large, walled bailey.
The thick walls were built at first of granite rubble, but as they gained height, brick was used instead. The change of materials suggests that this building carried a great deal of prestige, brick being a much more costly building material than stone.
This marked the beginning of the modern nation state of Sweden, and the Castle of Three Crowns became the principal residence of the monarchy.
During the "Great Power Period", after the Peace of West-phalia in 1648, extensive alterations were planned for the Palace, in keeping with Sweden's new-found status.
Work did not actually begin, however, until 1692, under the direction of the Palace Architect Nicodemus Tessin the Younger.
A disastrous fire on May 7, 1697 destroyed practically all of the old Palace, but the newly altered north wing was left more or less unscathed.
Six weeks after the fire, Tessin submitted drawings for the new Palace to the Swedish government. The plan was for the new Palace to be built in about five years.
In spite of the new Palace taking such a long time to build, the 1697 drawings were implicitly complied with. Work on the interiors began in the mid-1730s under the direction of the architect Carl Hårleman.
The Western Archway includes the Western Staircase, which was also the King's.
The east side of the Palace was the Queen's - the feminine side. The Eastern Archway includes the Queen's Staircase.
The east façade of the Palace is decorated with colossal pilasters, the reason being that in the old days it was visible all the way from Ladugårdsgärde (the area surrounding the present-day Telegraph Tower). The south façade represents the nation.
The centre of it, in the form of a gigantic triumphal arch, is the façade of the monumental Southern Archway, which is flanked by the Hall of State and the Royal Chapel: the Altar and Throne were the two poles of the good polity.
The north side of the Palace, overlooking Norrbro and Gustav Adolfs Torg, represents the more gentle aspect of royalty, since the main apartments of the King and Queen face this direction.
Offices were fitted out here for the cabinet and the ministries, the main debating chamber of the Swedish Riksdag (parliament) was here, and the Royal Library - the national library, in other words - was housed under the same roof.
The Royal Palace, quite simply, was a Sweden in miniature.