Knighthood, also referred to as chivalry, was a system of non-heritable gentry titles, bestowed on individual citizens of the Star Kingdom and Star Empire of Manticore as recognition for extraordinary service to the Realm.
Male knights were referred to as Sir, and female knights (actually Ladys) were referred to as Dame. Knighthood could be, and frequently was, in addition to other titles such as inherited noble rank or military rank. Thus, one might have Sir John Jones, Lord Bubbling Brook who could be referred to as Sir John, My Lord, or Lord Bubbling Brook. The wife of a knight was referred to as "Lady Jones" while there was no honorific for the husband of a knight. A female counterpart would be Dame Jane Smith, Duchess Meadow who could be referred to as Dame Jane, Lady Meadow, or Duchess Meadow.
These titles were also used by several ancient feudal societies on Earth, well prior to the Diaspora. The most influential of them in terms of a pattern to emulate was the ancient Kingdom of England, where the title was originally a minor military one, the rank a small landholder would have. More important landholders, whose vassals included knights, would have a higher rank, such as Earl, Count, Duke, Baron, etc. (HH1)
Manticoran orders of chivalry
- Detailed article about the concept of knighthood on Wikipedia