Elizabeth II and the centenary of the dogma of the Immaculate Conception both in 1954. In 1960, a set of stamps on stamps was issued for the centenary of the Halfpenny Yellow, and in 1962 a set of stamps was issued to commemorate the Great Siege of Malta of 1565. A set of stamps commemorating the award of the George Cross to Malta was issued in 1957, designed by the Maltese artist Emvin Cremona, who would design hundreds of Malta stamps until the 1970s. Other early stamp designs by Cremona include issues commemorating technical education (1958), other issues commemorating the George Cross award (1958, 1959 and 1961), the 19th centenary of St Paul's shipwreck (1960), an Anti-Brucellosis Congress (1964) and the First European Congress of Catholic Doctors (1964); the latter was issued two weeks before Malta became independent. Most commemorative issues from the mid-1950s until independence were printed by Harrison and Sons, but a few were printed by Bradbury Wilkinson or Waterlow. Independence and republic (since 1964) Malta achieved independence as the State of Malta on 21 September 1964, and on that day a set of six stamps was issued to commemorate the event. The stamps depicted a dove representing peace along with a British crown, a Papal tiara and the United Nations emblem. A definitive set depicting scenes from Malta's history was issued in 1965, and two additional values were issued in 1970. The independence and definitive sets were designed by Cremona, as were most stamps until the 1970s. Many stamps of the mid-1960s exist with flaws or errors such as missing colours, most notably the 1965–1970 definitive. Some stamps from this definitive were also issued in postage stamp booklets in 1970 and 1971. Malta adopted the Maltese pound or lira in 1972, and this event was commemorated by stamps showing the new coins. Some stamps of the 1965 definitive were subsequently surcharged in 1972 and 1977, and a definitive set in the new currency was issued in 1973. This set showed various scenes while the top value of £M2 was larger and depicted the country's coat of arms. Malta became a republic on 13 December 1974 and stamps commemorating this were issued in early 1975. The coat of arms was changed at this point, and a new version of the £M2 definitive was issued in 1976 to reflect this. Other decimal currency definitives depicted the history of Maltese