Sir
Sir is a title commonly given to men who have been knighted, but also as a way to address any male, especially if his name is not known. The equivalents for a woman are "Lady" and "madam".
Sir Media
Sir Thomas Troubridge, 1st Baronet, whose entitlement to use 'Sir' derived from his position as baronet
Emperor Taishō, a Stranger Knight of the Order of the Garter, who, as a foreign national, was not entitled to use the prefix 'Sir' (which as a sovereign monarch he would not have used in any case) but was permitted to post-nominally use KG
Chithira Thirunal Balarama Varma was the last surviving Knight Grand Commander of the Order of the Star of India.
Centennial stamp celebrating the Knights of Rizal released by PhilPost with a profile of Jose Rizal and the badge of the Order visible.