Baileys Irish Cream was invented in 45 minutes in 1973 by two ad creatives in Soho.
Hugh looked at me with an almost earnest stare. “What would happen if we mixed Irish whiskey and cream?” he said. “That might be interesting.”
https://www.irishtimes.com/culture/books/in-1973-i-invented-a-girly-drink-called-baileys-1.3240945