COIN (ROMAN)
A worn and corroded copper-alloy As of Agrippa, struck under the reign of emperor Gaius (Caligula), AD 37-41; 'Neptune standing left' reverse type; RIC Vol. I, p. 112, no. 58 (Cal). Measures 27.3mm in diameter, 2.3mm thick and weighs 8.68g. 

This coin shows Neptune on the reverse, alluding to Agrippa's victory (for Augustus) at the Battle of Actium in 31 BC, when Antony and Cleopatra were defeated. 

Ruler: Caligula
Denomination: As
Material: Copper alloy
Mint: Rome
Obverse: Head of Agrippa facing left, wearing (rostral crown).
Obverse legend: M AG[RIPPA L F C]OS III
Reverse: Neptune standing left, cloaked, holding trident and [dolphin].
Reverse legend: S-C
Dated: 37.0 to 41.0
Weight (g): 8.68
Diameter (mm): 27.3
Thickness (mm): 2.3
Completeness: Complete
Parish: Restricted Access
District: Uttlesford
County: Essex
Region: Eastern
Place known as: Chrishall
Discovery method: Metal detector