Question: When did Catherine Herbert, Countess Of Pembroke's husband die?
Sentence (from "Catherine Herbert, Countess of Pembroke"): She was born in Saint Petersburg, the daughter of Count Semyon Vorontsov (sometimes spelled Woronzow), the Russian ambassador in Britain from 1785, and the only sister of Prince Mikhail Vorontsov, Viceroy of New Russia and Caucasus (1782–1856).
Relevant evidence: No