Gerhard's exact parentage is uncertain, but he is considered to be a relative of the so-called
Matfriede and
Etichonid families. The options and many speculations have been discussed in detail by . Concerning his father, Hlawitschka has defended an early modern record which says Gerhard's father was a count of Metz named Richard. This Richard corresponds to records of a Richard in this position around 970-986, who was perhaps preceded by a count also named Gerhard. Hlawitschka proposed this Richard to be a grandson of
Godfrey, Count Palatine of Lotharingia, one of whose sons (possibly the one named Gerhard) was an ancestor of
Emperor Henry III, according to the eleventh-century biography of
Adelaide, Abbess of Vilich. Hlawitschka believes Gerhard's mother was a sister of the wife of the Etichonid count of the Nordgau in Alsace, whose son Hugh, and grandson
Pope Leo IX were described in various documents as blood relatives of descendants of Gerhard and his siblings. Gerhard's two siblings are known. • His sister,
Adelaide of Metz, married
Henry of Speyer, and their son was the future king of Germany, Conrad II. • His brother Adalbert, count in the
Saargau, succeeded Gerhard as Count of Metz. He is the earliest certain male-line ancestor of the main line of
medieval Dukes of Lorraine (
Upper Lotharingia), beginning with his grandson of the same name,
Adalbert, Duke of Lorraine. Much later, the 18th-century
House of Habsburg-Lorraine, were also direct descendants. Gerhard married Eva (or Abenza), a daughter of Count Sigfried of Luxembourg. Their only known son, also named Sigfried, pre-deceased them, and their daughter Berscinda, became Abbess of
Remiremont Abbey, where Gerhard was apparently the
advocatus (German
Vogt) of the abbey. {{tree chart| | | | | | | | | | | | |HEN| |ODA|v|GER| |MAT| |CUN| |HUG {{tree chart| | | | | | | | | | | | | OTT| | | |GOD| | | |ADL|-|LIU|v|EBH | {{tree chart| | | | | | | | | | | | | | | | | | |GER| | | | | | | | | | |!| | {{tree chart| | | | |SIG| | | | | | | | | | | |RIC|V|UN1| | | |UN2|v|RAU {{tree chart|HEV| |CUN|-|HN2| |EVA|v|GER| |ADT| |ADE|v|HNS| |HUG| ==Proposed county of Alsace==