In this paper our main focus is to provide insight into the history of M&A’s for this purpose we have analysed the different waves of M&A. We have analysed these waves in context of available literature and fact and figures. During the study we realised that almost all of the waves of M&A’s ended because of financial crises, although impact and severity of that crises may differ. We analysed the impact of current crises on M&A in global context and in order to establish how companies have and in post crises era i.e. after crises of 2007 onwards how the companies have changed their corporate strategies to accommodate M&A’s. We have also analysed which factors fuelled M&A’s in past and were these factors present in post crises era M&A activities. By first quarter of 2011 the many firms saw new growth opportunities in M&A activities seemed to rebound as large companies used M&A’s as part of their corporate strategy but this was cut short by events like US debt ceiling, down grade of USA’s credit ratings along with fears about Eurozone’s financial health and their impact on future prospects of M&A’s would they continue to prosper or would they be weighed down by these events.