Portraiture, one of the oldest and most captivating photographic genres, has roots dating back to the earliest days of the medium. Compiling a list of its most significant exponents is a daunting task, but this is what we've endeavoured to do: select what we consider the best portrait photographers of all time, each of whom has left an enduring mark on the style.

One of the finest photographers of her time, Ruth Orkin was an award-winning photojournalist and filmmaker, whose deeply absorbing images capture the charm and intrigue of quotidian life.