1814 First meeting between Princess Charlotte of Wales and
Prince Leopold of Saxe-Coburg-Saalfeld Her Wikipedia article has
this about the first meeting of Princess Charlotte Augusta and
Prince Leopold, "At a party at the Pulteney Hotel in London,
Charlotte met a Lieutenant-General in the Russian cavalry,
Prince Leopold of Saxe-Coburg-Saalfeld. The Princess invited
Leopold to call on her, an invitation he took up, remaining for
three quarters of an hour, and writing a letter to the Prince
Regent apologising for any indiscretion. This letter impressed
George very much, although he did not consider the impoverished
Leopold as a possible suitor for his daughter's hand." The
Duchess of Oldenburg is Catherine Pavlovna. She was then married
to Duke George of Oldenburg. The Wikimedia caption states 1818
or earlier, but this meeting occurred in 1814.