Recorded as Casius, Cassius, Casjens, Casjus (Germany), Cassio (Italy), and possibly others, this is a surname of Roman (Latin) origins. Curiously though it is only in Germany that it seems to have had any sort of hold in the above spellings, and even there only from the 18th century. The origination is believed to be the Latin word 'cassis' which originally described a helmet, or as casa, a castle. Ancient Rome had many prominent clan families, and that of Cassius was one of them. However as a surname it is probable that the origin is much more recent, and possibly 18th century. At that time many Christian or Hebrew people were obiged to flee areas under Muslim control in Central Europe, and they settled in Germany. There they were given abstract 'ornamental' surnames, which often were compounds such as Blomberg (flower hill) or Blomfeld (flower field), or historical names, of which Claudious and Cassius were examples. Recordings include Casparus Casius on October 26th 1747 at Mayen in the Rheinland, and Georg Frederich Cassius, baptised at Lissa Reformed Church, Posen, on April 14th 1850.