Nokia began as a mining and forestry company in 1865 and first entered telecommunications in 1963 developing radio telephones. Over time, Nokia expanded into electronics and merged with other Finnish companies to form Nokia Corporation focused on telecommunications. Nokia's mobile phones evolved from large portable radios in the 1980s to smaller feature phones in the 1990s and 2000s and smartphones running Windows Phone and Symbian operating systems. By 2013, Nokia's mobile phone business was acquired by Microsoft.