Flinders Petrie discovered the famine stella in 1887 on the Island of Sehel. The Famine Stella tells the story of Imhotep saving Egypt from a seven year famine and buying up the Land for his Pharaoh – Djoser (Netjerikhet).
Advance video to 2 minutes 35 seconds to see the discovery of the Famine Stella on the Island of Sehel
Flinders Petrie, who conducted numerous excavations in Egypt over a 40 yr period, also discovered the Merneptah stella in Thebes in 1896 and the Middle kingdom workers village of Kahun. He found evidence of a sudden mass exodus of slaves from Kahun in the 13th dynasty. From the well documented collection of scarabs that he found in Kahun, he was able to show that the village was occupied from the time of Sesostris II of the 12th dynasty up until Neferhotep I of the 13th dynasty.  
Petrie also developed a system of dating based upon pottery and ceramics found in the layers! 
 Flinders Petrie