It has ancient antecedents. A particularly famous example occurred in 226 BC, when the city of Rhodes was struck by a tremendous earthquake which wrecked havoc in the city and toppled the famous Colossus of Rhodes. The historian Polybius provides a list of the kings and potentates who offered aid to the (independent) city.

"For Hiero and Gelo [rulers of Syracuse in Sicily] not only gave seventy-five silver talents, partly at once and the rest very shortly afterwards, to supply oil in the gymnasium, but dedicated silver cauldrons with their bases and a certain number of water-pitchers and in addition to this granted ten talents for sacrifices and ten more to qualify new men for citizenship, so as to bring the whole gift up to a hundred talents. They also relieved Rhodian ships trading to their ports from the payment of customs, and presented the city with fifty catapults three cubits long. And finally, after bestowing so many gifts, they erected, just as if they were still under an obligation, in the Deigma or Mart at Rhodes a group representing the People of Rhodes being crowned by the People of Syracuse.

Ptolemy also promised them three hundred talents of silver, a million artabae of corn, timber for the construction of ten quinqueremes and ten triremes, forty thousand cubits of squared deal planking, a thousand talents of coined bronze, three thousand talents of tow, three thousand pieces of sail-cloth, three thousand talents for the restoration of the Colossus, a hundred master builders and three hundred and fifty masons, and fourteen talents per annum for their pay, and besides all this, twelve thousand artabae of corn for the games and sacrifices and twenty thousand artabae to feed the crews of ten triremes. Most of these things and the third part of the money he gave them at once. Antigonus in like manner gave them ten thousand pieces of timber ranging from eight to sixteen cubits in length to be used as rafters, five thousand beams of seven cubits long, three thousand talents of silver, a thousand talents of pitch, a thousand amphorae of raw pitch and a hundred talents of silver, while Chryseis his wife gave them a hundred thousand medimni of corn and three thousand talents of lead. Seleucus, the father of Antiochus, besides exempting Rhodians trading to his dominions from custom duties, presented them with ten quinqueremes fully equipped, two hundred thousand medimni of corn, ten thousand cubits of timber and a thousand talents of hair and resin. Similar gifts were made by Prusias and Mithridates as well as by the other Asiatic princelets of the time, Lysanias, Olympichus,and Limnaeus. As for towns which contributed, each according to its means, it would be difficult to enumerate them." (Polyb. 5.88.5-90.2).

All of these monarchs were so interested in helping Rhodes because Rhodes was a hugely important city. In the normal course of events, she was wealthy enough to pick and choose her benefactors. But the earthquake left her in need of so much help that she could hardly refuse anyone, and so ended up owing favors to half the kings of the known world.

There are probably even older examples of this sort of disaster-relief, though none spring immediately to mind. It was not uncommon for wealthy foreigners to donate to a particularly renowned temple if it was struck down by earthquake or fire. Nor was it uncommon for rulers to grant remissions in taxes and tributes to cities struck by some disaster. But neither of these types of benefactions as closely mirrors modern international disaster relief as the Rhodian example.