Ever since the East India and New East India Companies merged back in 1708, major companies have been joining forces to cut costs and increase market share. This year AT&T and Time Warner joined forces to the tune of $100 billion (£78.5bn), a move that risks putting AT&T into "terrifying" debt. But AT&T's former Chief Strategy Officer John Stankey (pictured), now CEO of WarnerMedia, will be hoping that with risk comes reward as the company seeks to reshape the media landscape. Read on as we reveal the 30 most costly corporate amalgamations of all time, adjusted for inflation.