The word "guard" in literal translation from Italian or English means "guard", "guard". In a broader sense, these are selected, privileged military units designed to perform a particularly difficult or honorable task.
The prototype of the guard in ancient times could serve, for example, the famous "Sacred Squad" of Sparta - the personal bodyguards of the Spartan kings. One of such detachments, led by Tsar Leonid, immortalized himself in the heroic battle of Thermopylae (480th year BC). By the way, in this battle the Spartans had a chance to meet with another guard detachment. In ancient Rome, the Praetorian corps could be considered a kind of guard, which in peacetime guarded the emperor and members of his family, and in war - performed the most difficult tasks.
In the Middle Ages, the main duty of the guard in many states was the protection of the ruling dynasty. Although, of course, the guards participated in the hostilities. A characteristic feature of the guard compared with other military units was: privileged position, better uniforms and weapons, higher monetary allowances, etc.
The first guard units in Russia arose during Peter the Great, when the former "amusing" regiments of the tsar - Preobrazhensky and Semenovsky - were awarded the status of "Life Guards" for their courage and staunchness in battles with the Swedish army of Charles XII. That is, in a literal translation from German of the "court guard" or "palace guard". Subsequently, the number of guard units increased markedly. The Guard played a large role in Russian history, since it was precisely its forces that carried out all the palace coups in the 18th century after the death of Peter I. Emperor Paul I was also killed in March 1801 by rebel guards. And most of the Decembrists who went to Senate Square were from the guard units.
But, of course, in addition to court battles, the Russian guard became famous on the battlefields. For example, in the famous Borodino battle as part of the 5th Infantry Corps, the Guards Division took part. The Life Guards Jaeger Regiment heroically fought for the village of Borodino, having lost most of its composition, the Izmailovsky and Lithuanian regiments withstood three attacks of the heavy French cavalry at the Bagration flashes, Semenovsky and Preobrazhensky fought at the Raevsky battery, and the Finnish at the Old Smolensk road.
After the October Revolution, the guard was abolished, and after the bloody battles near the town of Yelnya, it was born again in the Great Patriotic War. The four rifle divisions, the most distinguished, were converted into guard divisions. During the war, many units and formations deserved this honorary title.