NSU, originally known as "Neckarsulmer Strickmaschinen Union," was a significant German manufacturer of automobiles, motorcycles, and bicycles, founded in the late 19th century. The company's history can be traced back to 1873 when it started as a producer of knitting machines in the small town of Neckarsulm in Germany.

Over time, NSU evolved and expanded its production:

1. Motorcycles: NSU became a major producer of motorcycles in the early 20th century. The company gained a reputation for its innovative and high-quality designs. They were particularly successful in racing and set numerous speed records.

2. Automobiles: NSU started producing automobiles in the early 1900s. They developed a range of small to mid-sized cars and were known for their engineering innovations. One of the most notable cars was the NSU Ro 80, introduced in the late 1960s, which featured a Wankel rotary engine and a futuristic design. However, the Ro 80's technical problems and high costs ultimately led to financial difficulties for the company.

3. Merger and Audi: In 1969, NSU merged with Auto Union, which was owned by Volkswagen. This merger led to the formation of Audi NSU Auto Union AG, which eventually became simply Audi AG. The NSU name was gradually phased out as the focus shifted to the Audi brand.

NSU's legacy is significant in the automotive world, especially regarding its contributions to motorcycle engineering and its early experiments with the Wankel rotary engine. The company's innovative spirit and willingness to explore new technologies have had a lasting impact on the automotive industry.