The man who was Grand Prior of the Temple in England is also called Alan Marcel. If "Marcel" is an alternate spelling for Martel, Martial, then it merely means Alan "the Warrior" and should not be taken as a surname of any kind. Also called "Alanus Marcel" he is represented in stained glass and is likely one of the effigies in the circular Temple Church still existing in downtown London.
Burke's Landed Gentry, "Symons of Hart" has the following claim: "Nicholas Fitz Richard of Suffield father of Peter FitzNicholas of Suffield and Fritton who m Alice dau and heir of William de Suffield and d in 1218 leaving with a younger son Alan a knight templar and crusader, a son and successor Simon Fitz Peter of Suffield living in 1235 who m Nichola dau of Robert Curlew of Threxton and had an only son Simon Fitz Simon...."
In "The History of the Knights Templar: The Temple Church and The Templars", page 131, by Charles G Addison we find the following statement: "The results of that disastrous campaign [in 1222 wj] are detailed in the following letter to Brother Alan Marcel, Preceptor of England, and Master of the Temple at London....Brother Alan Marcell, to whom the above letter is addressed, succeeded Amaric de St. Maur, and was at the head of the order in England for the space of sixteen years. He was employed by king Henry the Third in various important negotiations; and was Master of the Temple at London...." He also mentions that Alan was mentioned Grand Prior or Grand Preceptor in England citing Acta Rymeri and Matthew of Paris in 1224. But then it changed to the templar Amberaldus by 1229.
The depiction of the arms at Ribston however don't seem to support the idea of this Amberaldus as Grand Prior.
The Wikipedia article, "List of Knights Templar" contains the following claim: "Alan Marcell, occurs 1220 and 1228". "Alan Marcel, Master of the Temple in England" appears in 1223 here. "Alan le Templer" occurs in the CPR in 1254 here, and here delivering money out of the treasury of England. There are, by the way, no persons named Fitz Nicholas or Fitz Piers (Fitz Peter) in the CPR this early.
Burke's Landed Gentry, "Symons of Hart" has the following claim: "Nicholas Fitz Richard of Suffield father of Peter FitzNicholas of Suffield and Fritton who m Alice dau and heir of William de Suffield and d in 1218 leaving with a younger son Alan a knight templar and crusader, a son and successor Simon Fitz Peter of Suffield living in 1235 who m Nichola dau of Robert Curlew of Threxton and had an only son Simon Fitz Simon...."
In "The History of the Knights Templar: The Temple Church and The Templars", page 131, by Charles G Addison we find the following statement: "The results of that disastrous campaign [in 1222 wj] are detailed in the following letter to Brother Alan Marcel, Preceptor of England, and Master of the Temple at London....Brother Alan Marcell, to whom the above letter is addressed, succeeded Amaric de St. Maur, and was at the head of the order in England for the space of sixteen years. He was employed by king Henry the Third in various important negotiations; and was Master of the Temple at London...." He also mentions that Alan was mentioned Grand Prior or Grand Preceptor in England citing Acta Rymeri and Matthew of Paris in 1224. But then it changed to the templar Amberaldus by 1229.
The depiction of the arms at Ribston however don't seem to support the idea of this Amberaldus as Grand Prior.
The Wikipedia article, "List of Knights Templar" contains the following claim: "Alan Marcell, occurs 1220 and 1228". "Alan Marcel, Master of the Temple in England" appears in 1223 here. "Alan le Templer" occurs in the CPR in 1254 here, and here delivering money out of the treasury of England. There are, by the way, no persons named Fitz Nicholas or Fitz Piers (Fitz Peter) in the CPR this early.