Winston Leonard Spencer Churchill was born November 30, 1874 at Blenheim Palace, home of his grandfather the 7th Duke of Marborough. His birth was unexpected; his mother went into labor after "a rather imprudent & rough drive in a pony carriage." Despite the circumstances of his premature birth, the infant Churchill was "wonderfully pretty" with "dark eyes and hair & v[er]y healthy."

This London cover is postmarked on the day of Churchill's birth, November 30, 1874. The folded letter to Copenhagen was received there on December 2nd.

Close-up of the stamp and postmark.
I spent years searching for a British cover of this date.

This cover was postmarked at Blenheim on the 100th anniversary of Churchill's birth.

Postmarked at Blenheim, SC, November 30, 1999.