The Italians were always at it in the Balkans, it seems. In my previous post I dealt with their occupation of the Ionian Islands during WW2, but they also invaded the islands in the 1920s. When the Italian general Tellini, part of a committee to establish the borders between Greece and Albania, was murdered at the spot, on Greek territory, the Italians occupied Corfu, from August 31, 1923 onwards. The occupation lasted for about a month but a lot of postal activities took place during that short period.
Before special stamps could be issued, normal Greek stamps were used during the occupation. But on 20 September 1923, a set of eight Italian stamps with the overprint CORFU were issued.
Four days later the first stamps with both the CORFU overprint and a new value in Greek currency arrived on the island.
Again three days later, the Italians ended the occupation and left the island. Three more of those stamps with name and new value overprinted were ready for shipment but as it was anticipated they would not arrive on the island of Corfu before the Italians would have evacuated, these three stamps were never issued.
They have, however, ended up on the philatelic market and have even been awarded general catalogue inclusion!