Reginacide

However, my old enemy, Miss [Edith] Sitwell, is now enthroned. I was not at the coronation, I am not among her subjects. But I have no inclination left to be a reginacide or even a jeering republican.

Source: wiktionary

Another report connects the incident with the trial of the would-be reginacide John Somervyle (1 Anderson 106).

Source: wiktionary

Touring Ghana with Her Majesty Queen Elizabeth II (next page), His High Dedication Kwame Nkrumah—that is his title—has learned that the image of a true queen is not easily removed from the hearts of ex-colonial Africans. Increasingly unpopular because of his police-state methods, Nkrumah used the queen’s visit as a pretext to jail dozens of his political opponents as would-be reginacides.

Source: wiktionary

George Henderson has proposed recently that Guthlac’s hasty retreat to Repton in 697 could be explained by his early secular career having been brought to an abrupt end by an involvement in the murder of Queen Osthryth of Mercia (wife of King Æthelred) that same year – the two events appear together in the annal entry for 697 in the Worcester Chronicle. Henderson would interpret Guthlac’s sudden discovery of a religious vocation as a means of escaping a worse fate when retribution was sought for the queen’s death. Presumably Guthlac’s retreat to the fenlands could then be seen as a form of political exile not unlike that of Æthelbald, and in this context Henderson draws attention to the attempted assassination of Guthlac by Beccel as perhaps being not so much a hagiographical motif as a real attempt by the Mercian regime to take revenge on a reginacide.

Source: wiktionary