Systematic destruction of the Ottoman empire throughout Mediterranean Europe (e.g. "classical" Greece) and Africa (e.g. all of "North Africa") describes concisely the impetus of "shared history"

Being repeatedly at war with each other doesn't mean countries do not share a common history, culture and even economy: European kingdoms have been at war for centuries. By the way, the Ottoman empire was seen as a European state until its end: during the XIXth century, it was nicknamed "the sick man of Europe". Political and military alliances were made with it (by France and the Republic of Venice, for example) and there was a huge volume of trade with it throughout its history.

"Ce qui vient au monde pour ne rien troubler ne mérite ni égards ni patience." René Char