All images were found on wikimedia commons and scaled down for redistribution.

RRC_452-2_Julius_Caesar_coin.jpg
  This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1924.

Aureus,_Auguste,_Lyon,_btv1b104440369.jpg
Monnaie_de_Bactriane,_Eucratide_I,_face.jpg
Eucratide_1er_-_20_stateres.jpg
  This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

1000_rupiah_coin_reverse.jpg
200_rupiah_coin_obverse.jpg
  This file is in the public domain in Indonesia, because it is published and distributed by the Government of Republic of Indonesia, according to Article 43 of Law 28 of 2014 on copyrights.
    There shall be no infringement of Copyright for:
    * Publication, Distribution, Communication, and/or Reproduction of State emblems and national anthem in accordance with their original nature;
    * Any Publication, Distribution, Communication, and/or Reproduction executed by or on behalf of the government, unless stated to be protected by laws and regulations, a statement to such Works, or when Publication, Distribution, Communication, and/or Reproduction to such Works are made;
    * Reproduction, Publication, and/or Distribution of Portraits of the President, Vice President, former Presidents, former Vice Presidents, National Heroes, heads of State institutions, heads of ministries/nonministerial government agencies, and/or the heads of regions by taking into account the dignity and appropriateness in accordance with the provisions of laws and regulations

