Which trend did the Duchess of Bedford start in the 1840s?

"Thank you, Your Grace. I'll take mine with a little lemon, and some of those delicious-looking sandwiches."

The seventh Duchess of Bedford was Anna Maria Russell. Around 1840, she is credited with devising afternoon tea.

At that time, urbanisation and the industrial age meant that evening meals were much later, stretching the time period from lunch.

Her Grace was one of Queen Victoria's ladies-in-waiting and came up with the late-afternoon snack to make life easier for the wealthier classes: a ritual they were delighted to follow.

https://www.britishmuseum.org/blog/tea-rific-history-victorian-afternoon-tea