This, according to legend, is Nader Shah's

Nader Shah

Nāder Shāh Afshār ruled as Shah of Iran and was the founder of the Afsharid dynasty. Because of his military genius, some historians have described him as the Napoleon of Persia or the Second Alexander...

 "All Conquering Sword" though the inscription on the blade attributes it to Fathali Shah. The sword is not visible in any of the portraits of Fathali Shah

Shah

Shāh is the title of the ruler of certain Southwest Asian and Central Asian countries, especially Persia , and derives from the Persian word shah, meaning "king".-History:...

. There is, however, a mural in the Marble Room of the Golestan Palace which shows Mohammad Shah Qajar

Mohammad Shah Qajar

Mohammad Shah Qajar was king of Persia from the Qajar dynasty .- Rise to power :...

, the successor to Fathali Shah, wearing the sword while on horseback.

Both sides of the handle and hilt are covered in diamond

Diamond

In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

s. The length of the sword is 100 cm. (3.2 ft.) and the largest of the 850 large diamonds on the sword is 20 cts.

The reverse side of the sword and scabbard shows a picture of the Shah on the hilt along with a few lines of verse, and the pictures of two of his sons.