The article provides rationales to the notion that the share of gas in the future EU energy mix is to be determined, among other factors also by the prospects of diversification of ‘pipeline gas’ supply and the resulting perception about the stability of supply and prices in future. The best, if not the only source of such diversification is the Caspian gas supply, but in order to serve for the purpose it needs to be of a strategic magnitude. EU has started to look for diversification options to mitigate thedominant supplier effect on the market, but with problems accumulating with ‘Nabucco only’ approach, EU have switched to more complex and comprehensive multi-project ‘Southern Corridor’ scheme with stated strategic goals of delivering 45-90 bcm of gas annually. An important difference of the new approach is the introduction of notion about the synergy and risk reduction effect of having routes across Turkey and across the Black Sea in parallel. Consequently separate sets of competing projects have been identified for both directions: along with well-known projects via Turkey, the Black sea projects like White Stream, AGRI and Bulgarian CNG project has been given political and financial support by the EC or in latter cases by White Stream has been included in the TEN scheme and was granted the status of a EU priority project of the Common Interest. Numerous factors, expected and unexpected have hindered the progress in the past years, but the path taken lately provides for securing success. That includes MS mandate for EC for negotiating trance-Caspian pipeline solution, identifying TCGP as a major Southern Corridor project, the CDC developments. Suggested TANAP development has planted confidence on finally launching a project via Turkey, absence of which was also preventing a start of advanced development of the Black Sea route. Implications for Black Sea area energy security discussed, exploring the role of NATO.