74 years to this day in 1947 when Princess Elizabeth visited Radley College in Oxfordshire in this most interesting bonnet design with flat frown and ruffle trimmed brim.
Our thoughts and well wishes are extended to the Queen today, on what would have been Prince Philip’s 100th birthday.
Images from Getty as indicated
Royal Hats 
Love the flat frown!
I love the upturned brim and the trim on it, but the crown looks like a plate underneath a china cup turned upside down!