Queen Geraldine of Albania survived 41 years her husband King Zog I
Queen Giovanna of Bulgaria survived almost 57 years her husband King Boris III
Maria Feodorovna (Dagmar of Dk) survived 34 years Tsar Alexander III
Her d-i-l Natalia Cheremetevskya, cr Pss Romanovskaya-Brassova, survived 34 yars GDk Michael.
Pss.Helena of Serbia survived 44 years GDk Ivan of Russia
GDss Tatiana Constatinova survived 57 years her 3nd husband Alexander Korochenzov
That Princess Emma of Waldeck and Pyrmont was widowed early was no surprise, since she married (as his second wife) King Willem III of the Netherlands, who was more than 40 years her senior. The same could be said of her sister Helen, who married Prince Leopold of the United Kingdom, Duke of Albany -- the hemophilic youngest son of Queen Victoria. Although both widows were young enough to catch new husbands, neither remarried. As such, they had long widowhoods (44 and 38 years, respectively).
Emma's Spanish counterpart, who was born Archduchess Maria Christina of Austria and became the second queen consort of King Alfonso XII, was also widowed early and found herself serving as regent for a minor sovereign. Her widowhood also lasted 44 years.
Other notable examples of long widowhoods are those of Great Britain's Queen Victoria (39 years) and Queen Elizabeth, the Queen Mother (50 years); Infanta Antonia of Portugal (52 years), second wife of Duke Roberto of Parma; Princess Zita of Bourbon-Parma (67 years), the last empress of Austria; and Princess Adelaide of Löwenstein-Wertheim-Rosenberg (43 years), wife of Dom Miguel of Portugal.
Can anybody name additional examples of notable royal women in the last 200 years, who were longtime widows (at least 30 years)?