Amal Clooney looked beautiful and stylish at her arrival in Heathrow Airport. In black and grey, her brocade dress / coat is probably by Dolce Gabbana.
I found a similar dress by Dolce Gabbana €4,696.71
Still available on Net-a-Porter
The boots are by Prada, currently sold out
Black Suede Backzip Platform Ankle Boots