Huge crowds will attend the Pope's visit to Zagreb to honour the 900th anniversary of the diocese. Poland may claim to be semper fidelis, but Croatia rejoices in the no less illustrious title of the 'Rampart of Christendom', an attribute bestowed by one of the lesser-known popes of the early Middle Ages.
As the Pope journeys northwards from Zagreb to the ancient Marian shrine of Marija Bistrica, the visit will appear, rightly, as a gesture of blessing from a deeply anti-Communist, Slav, Catholic pope to a deeply anti-Communist and Slav Catholic nation.
The orgy of mutual backslapping will, no doubt, kick over the traces of the diplomatic footwork which has preceded the visit. A Papal visit to a united Yugoslavia was on the cards years ago. But as the country dissolved on confessional lines, and Roman Catholic Slovenes and Croats declared independence, the Pope's projected visit assumed a new dimension.
Orthodox Serbs, dwelling on the Catholic hierarchy's position in the fascist Croatian state during the Second World War, insisted on exaggerating the Vatican's role in securing diplomatic recognition for breakaway states, and distorted Rome's motives.
In fact, the Vatican and the Roman Catholic hierarchy got their fingers burned badly in the war and have been determined not to get caught the same way. Although the Belgrade media fulminate excitedly about a 'Vatican crusade' against Serbia, the Holy See plays a subtler game than this - it did not shrink from cold-shouldering Catholic Croats, when they roughly handled Bosnia's Muslims.
There were sound reasons for the Holy See's caution. Mr Tudjman seemed ready to sacrifice central Bosnia to the Muslims in order to annex the strategic Dalmatian hinterland of Herzegovina. The Croatian hierarchy did not share Mr Tudjman's agenda; it saw central Bosnia, with its web of historic monastaries, as the beating heart of Catholic Bosnia and viewed with horror its proposed sacrifice to a Muslim Bosnian statelet in the interests of Zagreb's realpolitik.
Croatia's Catholic bishops will want the Pope to play a vital role in cementing the fragile process of reconciliation between Catholics and Muslims in Bosnia. It is a role the Pope will relish. Papal hopes of bridging the chasm between Catholics and Orthodox are less likely to yield fruit.
Although he would like to touch down in Belgrade, Serbia's Orthodox hierarchy have made it quite clear that they do not want His Holiness on Serbia's sacred soil. There are nearly 2 million Albanians in Serbia, some of whom are Catholic, as well as 350,000 Catholic Hungarians. There lurks a fear that a Papal visit might encourage these cowed minorities to become 'uppity', and to demand some of the same rights claimed by Serbs in Bosnia and Croatia.