This effigy in Montgomery Church is probably Sir Edmund Mortimer. Sir Edmund was defeated by Owain Glyndwr but later married his daughter. Beside the tomb are two effigies on the floor. There has been much speculation about who might these belong to, the current thought is the larger is Sir Edmund Mortimer, son-in-law of Owain Glyndwr and brother-in-law of Henry "Hotspur" Percy. He was called "revolted Mortimer" by Shakespeare and he died in 1408 or 1409 during the siege of Harlech. (However, there is a plaque in Wigmore Abbey that claims that Edmund is one of the eleven members of the Mortimer family buried there.) The other is thought to be Sir Richard Herbert, grandfather of the occupant of the adjoining tomb, who died in 1534

(Link)
Effigy of a Mortimer knight in the church of St Nicholas in Montgomery, Powys. It has been suggested that it could be Sir Edmund Mortimer (d1409) brother of the 4th Earl of March.

(Link)

(Link)
Yet although Edmund was born im lawful wedlock, the Mortimer shield on this tomb bears a band (or baton) sinister, which denotes bastardy and in the Middle Ages was often used for royal bastards.

похож на костюмы из отдаленных графств P0233, 1395 (London) и P0221, 1395 (Horsham, Sussex West), что можно объяснить близостью к королевской семье и, таким образом, к лондонской моде в одежде

костюм можно датировать раньше - 1390-е, так как пояс, завязанный узлом, в 1400-х встречается крайне редко (см. P0233, 1395; P0538, 1392)
поэтому возможно, что памятник был изготовлен при жизни персонажа, вероятно, вскоре после смерти его старшего брата, Roger de Mortimer, 4th Earl of March, в 1398 году