First Dutch king since 1890

With his 75-year-old mother signing an act of abdication at Amsterdam's Royal Palace on Tuesday morning, Willem-Alexander has become the king of the Netherlands. His Argentine-born wife, Maxima, is now queen, and their eldest daughter, 9-year-old Catharina-Amalia, has become Princess of Orange and heir to the throne.

"It is my deep wish that the new royal couple will feel themselves supported by your loving trust," Queen Beatrix said on Monday. "I am convinced that Willem-Alexander will apply himself with true devotion to everything a good king is obliged to do," she added.

The day is expected to be a huge party, culminating in a boat trip by the royal couple around the Ij waterway. Security was also tight, with 10,000 uniformed police, 3,000 plainclothes officers and an untold number of civil servants assisting in the logistics. On Monday, officials closed the airspace above Amsterdam for three days, and Dutch police, German agents and sniffer dogs swept Dam square for bombs.

Meeting of monarchies

Royalty from 18 countries made the trip, including Britain's Prince Charles and his wife Camilla, and the Japanese Crown Prince Naruhito and Crown Princess Masako. Charles also attended Beatrix's coronation in 1980.

Beatrix announced her intention to step aside in January after 33 years on the throne. She succeeded her mother, Juliana, who abdicated in 1980.

In her abdication speech Monday, Beatrix said she had "shared both joy and national pride" with her people as well as their "sorrow and anxiety."

mkg/msh (Reuters, AFP, dpa, AP)