This joint issue of the Spanish and Portuguese Posts marks the simultaneous admission of both countries to the European Economic Community (now the European Union), on January 1st 1986, arguably one of the most important events in modern Portuguese history. Over the following years, the financial help of the EEC, partly squandered, and a new legal and financial framework helped Portugal modernise itself quickly after four decades of stagnation due to the fascist regime. The admission protocol was signed by the EEC and Portuguese representatives in the Jerónimos Monastery on 12 June 1985, after 8 years of negotiations.
The image shows the joint first day cover, with stamps and cancellations from both countries, and sent by road from Madrid to Lisbon. Interestingly, the Spanish cancellation mentions both countries and has the logos of both postal authorities, whereas the Portuguese cancellation reprises the hexagon motif and omits Spain. Not very courteous.
The stamps were designed by Acácio Santos (hexagons) and FNMT (map), and issued on 7 January 1986. The Portuguese issue was lithographed by the Mint on enamelled paper sheets of 5×10 stamps with perforation 12×11¾ and a phosphor band, and circulated to 31 December 1992. The Spanish issue includes two further stamps. The Spanish stamps have perforation 13½×13.