Alexandrium

Alexandrion or Alexandrium, sometimes referred to as Sartaba, was a fort constructed by the Hasmoneans on a mountain between Scythopolis and Jerusalem, near the Jordan Valley. It was likely named after Hasmonean king Alexander Jannæus (104-77 BCE).

History
Alexandrium was constructed by the Hasmoneans near the border with Samaria to accommodate a military garrison, as well as to guard political prisoners. It is later mentioned during Pompey the Great's conquest of Judea as a stronghold of Aristobulus II: "When, in the year 64, Pompey marched past Pella and Scythopolis to Coreæ, on the northern boundary of Judea, Aristobulus II fell back on Alexandrium."

The fort was restored by Herod the Great, a task he assigned to his brother Pheroras. Herod used the fort as a prison for his political opponents, holding his wife Mariamne and mother Alexandra there in 30 BCE. It was also the burial site of Alexander and Aristobulus, the two sons Herod had executed at Sebaste in 7 BCE.

Alexandrium was finally razed by Vespasian or Titus during the Great Revolt.