early 14c., reconisaunce, in law, "a bond acknowledging some obligation binding one over to do some particular act," from Old French reconissance "acknowledgment, recognition" (12c., Modern French reconnaissance), from reconoiss-, present-participle stem of reconoistre (see recognize).
By c. 1400 as "acknowledgment of subjection or allegiance" (to God or a temporal power). The general sense of "act of recognizing, acknowledgement of a person or thing" is from 15c. To be discharged or released (up)on (one's) own recognizance (1851) as a phrase for "be released without bail on condition of good behavior" in the jargon of police blotters and district courts, is based on the written promise that you sign to get it, to appear in court as required. Related: Recognizant.