Story highlights Microsoft announced it is buying Nokia's mobile phone division

Despite smartphone struggles, Nokia has been a mobile leader

It was the first to switch to an international mobile-networking system

Nokia introduced phone gaming and the "slider" style of handset

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:

First to move

It's not the sort of thing that smartphone owners today probably remember -- if they're even old enough. But the Nokia 1011, released in 1992, was the first commercially available mobile phone that operated on what's called the GSM network.

The letters stand for Global System for Mobile. And what that meant was that unlike earlier phones, the Nokia could be used to make a phone call from almost anywhere in the world. GSM is still the world's most widely used mobile system, although 4G is expected eventually to replace it.

Phone as fashion statement

A phone is just a phone, right? Of course not.

Today, there are plenty of folks who, admit it or not, wrap at least a small part of their identity up in what kind of phone is in their pocket.

That was a pretty alien concept up until the early 2000s when, if you owned a cell phone, there was a pretty good chance it was a Nokia. Remember those chunky, rounded models with the tiny gray screens and the nubby antennas?

The Nokia 5110 was one of the most popular. And it also was one of the market's first phones that had a replaceable face plate. The plates came in a wide variety of colors, offering one of the first chances to personalize your phone's look.

The 'slider'

The popularity of early Nokia phones meant the company's designs often became the standard for cell phones.

It didn't create the first flip phone (that honor belongs to Motorola), but the "slider" was all Nokia. The first was the company's 8110 model, which debuted in 1998. How cutting edge was the design at the time? It was the phone of choice in the futuristic 1999 sci-fi film "The Matrix."

Mobile gaming

Remember "Snake"?

It seems laughably simple compared with the range of gaming possible on today's smartphones. But plenty got addicted to this game.

Even though it had already been in arcades, Nokia began preloading "Snake" on its phones in 1998.

Don't hit your own tail. Don't hit the walls. And what the heck were those things you were eating, anyway? Who knows -- but "Angry Birds," "Candy Crush" and their app-store brethren owe a tip of the digital cap to Nokia's vision of telephone-as-gaming-device.

Windows warrior

Phones running the Windows operating system haven't exactly set the marketplace on fire. In the second quarter of this year, 7.4 million phones running Windows were sold, according to Gartner Research. That's a long way behind the No. 2 system, Apple's iOS, with 31.9 million phones sold in that time.

But Nokia has squarely positioned itself as the leading vendor of those Windows phones, making 82% of the devices sold last year. In 2011, Windows and Nokia announced a partnership in which Nokia switched to the Windows OS as the default system running all of its handsets.

That hasn't been enough to put Nokia on super-solid ground, at least not yet. But the longstanding partnership is what led to Monday's purchase, and if having in-house hardware gives Windows Phone a boost, Microsoft and Nokia will reap the rewards.