TOKYO - Japan's Crown Princess has attended a banquet for visiting Dutch royals, her first such appearance in 11 years.

Princess Masako, the 50-year-old wife of Crown Prince Naruhito, also attended a welcoming ceremony for King Willem-Alexander of the Netherlands and his wife Queen Maxima at the Imperial Palace on Wednesday, according to media reports. It was her first welcome ceremony appearance in five years.

Princess Masako began to suffer from a stress-related illness after joining the imperial family in 1993. Since the birth of her daughter Aiko in 2001, she has made rare public appearances but has largely stayed away from royal duties.

Princess Masako and Crown Prince Naruhito travelled to the Netherlands last year to attend King Willem-Alexander's inauguration in what was seen as a sign of her recovery, reported BBC.

Before marrying the Crown Prince, Princess Masako was a successful diplomat who spoke several languages and travelled extensively.

Observers say she had an abrupt transition from her cosmopolitan lifestyle to the rigidity of royal life in Japan, said the BBC report. She was diagnosed with "adjustment disorder", which is linked with symptoms of depression and anxiety.

Many blame her ill health on the pressure to produce a male heir to the Chrysanthemum Throne as the royal family went through a succession crisis. But the crisis was resolved when Crown Prince Naruhito's younger brother, Prince Akishino, and his wife, had a son in 2006.