(CNN) -- With its purchase of Nokia's mobile phone business, Microsoft has brought a longtime partner into the fold to help fight a battle that has been tough for both companies. Microsoft, which was late to the smartphone game with its Windows mobile operating system, badly trails Android and Apple's iOS. And while Nokia is still a force selling feature phones worldwide, it's barely made a dent in the smartphone market. But if the Finnish company is struggling today, it can still take pride in its history at the forefront of the mobile movement. Here are five ways the once-dominant phonemaker has helped shape the world of mobile electronics as we know it today:
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Microsoft announced it is buying Nokia's mobile phone division
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Despite smartphone struggles, Nokia has been a mobile leader
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It was the first to switch to an international mobile-networking system
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Nokia introduced phone gaming and the "slider" style of handset
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