Edward Ernest Sikes, 1911 Encyclopædia Britannica (1911)
“ So, although the warlike character of Hera was not elsewhere prominent, she assumed a militant aspect in her two chief cities; a festival called the Shield (ἀσπίς, in Pindar ἀγὼν χάλκεος) was part of the Argive cult, and there was an armed procession in her honour at Samos. The city-goddess, whether Hera or Athena, must be chief alike in peace and war. The cow was the animal specially sacred to Hera both in ritual and in mythology. The story of Io, metamorphosed into a cow, is familiar; she was priestess of Hera, and was originally, no doubt, a form of the goddess herself. ”
