Second Council of Nicaea

Illustration of Christ on the Cross: "They gave me gall to eat; and when I was thirsty they gave me vinegar to drink" accompanied by miniature depicting iconoclasts John Grammaticus and Anthony I of Constantinople rubbing out a painting of Christ with a sponge attached to a pole. Chludov Psalter (9th century), Moscow, Hist. Mus. MS. D.129.

Decrees of the Seventh Ecumenical Council (A.D. 787) which was summoned to address the issue of iconoclasm. The council declared the production and exposure of art representing Christ and the saints to be an authentic ecclesiastical tradition in harmony with the spread of the gospel. Image above links to Tanner translation. ISBN recommendation: 0-87840-490-2.  For a more detailed defense of holy art, see St. John of Damascus: Apologies Against Those Who Attack the Divine Images in Appendix I.