In the world of Fate/Grand Order or FGO, the concept of Grand Servants is one of the important elements that distinguishes them from ordinary Servants. Grand Servants are legendary entities chosen by Alaya as representatives of humanity's maximum power to face threats that threaten the safety of humanity, especially Beasts, the highest-ranking creatures that are the main enemies of humanity's existence.

Grand Servants are a special class of Servants that can only be summoned in emergencies or when humanity is on the brink of destruction. They are the strongest in their class, not only because of their physical strength, but also because of their historical capacity, symbolism, and role in maintaining the continuity of civilization. Not all legendary heroes can become Grands. Some factors to consider include:

• The scale of history and its impact on humanity globally.
  
  
• Loyalty to the survival of mankind(not neutral or opposing).
  
  
• Eligibility in terms of strength and mentality, because they have to face the Beast which is the embodiment of humanity's greatest curse.
  
  

So far in FGO only the identities of 4 Grand servants have been revealed, namely Grand Assassin, Grand Archer, Grand Lancer and also Grand Caster. However, there is 1 Grand Servant whose identity only exists in the arcade version of FGO, namely Grand Rider.

Hassan I Sabbah is a Grand Assassin who appeared in the Babylonian singularity to help Chaldea in her fight against Beast II Tiamat who wanted to destroy the entire world. With his Noble Phantasm Azrael Grand Assassin was able to give the concept of death to Tiamat which allowed Chaldea to defeat Tiamat.

The second Grand Servant to appear in FGO is Orion who holds the title of Grand Archer. He manifested himself to help the chaldea duo against the god of olympus who turned into a machine god. Orion's presence there is the will of Alaya who wants to get rid of the threat that can destroy humanity.

Romulus Quinirus is a Grand Lancer who appears from the collective desire of humanity in fighting the gods of Olympus because of Romulus's connection with the concept of Rome which allows him to be summoned by Chaldea through Caenis. Romulus' role in battle is when fighting Zeus who is the strongest god machine.

The Grand Caster position was originally filled by Solomon but is now empty because Alaya once summoned Solomon to defeat Beast I Goetia but Solomon's body was taken over by Goetia and created chaos called singularity. This is the main trigger for the events of the FGO kissah.

In the future, players are eager to see other grand servants and what roles they will play in the FGO story in the future.