The buyer cannot rely on remedies when any supervening event, such as war, trade embargo, closure of the international waterways, or so forth, has occurred subsequent to the concluding of the contract. In such a case, subject to certain qualifications, the seller will be exempted from liability for non-performance of his contractual obligations. This principle is well established in all legal systems,1 and plays a very important rule in inter national trade, since supervening events in international transactions pre sent greater effects on the performance of the contract than on local contracts.2 However, domestic legal systems have not adopted one theory for exemption. Several terms (such esforc? majeure, frustration, impossibility, Act of God, impracticability, and hardship) have been used for the achieve ment of the same goal, but with different concepts, scopes, and effects on the contractual obligations. This Article will deal with the elements of the supervening events under selected legal systems, namely, the Vienna Convention on Contracts for the International Sale of Goods (hereinafter CISG), English law, in particu lar the Sale of Goods Act 1979, as amended (hereinafter SGA), and the Libyan Civil Code (hereinafter LCC); reference is also made, when it is necessary, to the Uniform Law on the International Sale of Goods, the Hague Convention 1964 (hereinafter ULIS).