William Mosset was born in the village of Hölstein on 3 June 1909. He went on to complete his training as a precision mechanic in the same small settlement. Young William spent what little spare time he had tinkering and experimenting in the simple workshop he had established for himself in the cellar of the family home.

It wasn’t long before William made his first invention. In spring 1929 he developed a tool that could punch 32 holes cleanly, precisely and simultaneously into a pillar-plate. He put his new expertise at the disposal of his then employer; but the invention also enabled him to found a company of his own.

Putting his further education plans on hold, William joined the Oris company to learn the skills of watch manufacture. At the age of just 22, he was appointed Head of department “Assortiment”, the department responsible for production of the movement’s assortment (escape-wheel, pallets and roller). Despite the sizeable responsibility with which he had been entrusted, this visionary, resourceful and ambitious young manager was sceptical of his further career prospects at Oris, and resolved to establish his own company within the watch manufacturing sector at the earliest opportunity.

Alongside his Oris manufacturing duties, William completed a distance learning course in the evening hours. He also invented a series of small pivoting and polishing machines for use in the watch manufacturing industry. His greatest achievement, though, he regarded as the development of the “Carousel”, a milling and drilling machine that enabled 20 operations to be performed one after the other in a circular process. And on 1 November 1944 William Mosset took the bold step of setting up his own company, with an initial workforce of seven employees.

With the Second World War over, William Mosset was finally able to put his building plans into practice. On 19 March 1946 it was time to enter the new company in the Commercial Register. But under what name? In the end, William was inspired by the French term “arrondir”, referring to the rounding off of the pivot. Ronda was born; and the company moved into its new factory in the town of Lausen on 18 November of the same year.

In its early years, the Ronda company and its 45 employees manufactured balance staffs, stems and pivots for lever movements. With the acquisition of a patent, assortments for pin-pallet and Roskopf movements of other manufacturers were incorporated into the production programme; and regulated balances were added in 1958.

From 1952 onwards, Ronda produced the first blank Roskopf and pin-pallet movements (also known as ébauches) under licence for the Brac company, which was based in Breitenbach in Canton Solothurn. Ebauches differ from complete mechanical movements in that the escapement, the balance and the mainspring have not yet been added. By the time the 1950s were drawing to a close, Ronda’s Lausen workforce had grown to 220 personnel.

For many years, the Swiss authorities protected the watch manufacturing industry by legislation which, among other things, granted ébauche production rights solely to its major players. After a long and tough battle, Ronda finally won the right in 1961 to manufacture its own pallet and Roskopf blank movements. The company also manufactured the entire assortment of these mechanical movements in the form of components such as escape wheel, pallets and balance with its staff. The manufacture of assortments for other brands was abandoned around this time.

By spring 1971 Ronda could already look back on a quarter-century of eventful company history. The original operation had been substantially expanded with the addition of five further buildings. The site workforce had grown accordingly to 520 employees, with a further 375 personnel working from home. Despite the spacious premises, though, the company’s Swiss Made movement assembly activities (also known as “T1”) had to gradually be outsourced. In the same year, Ronda acquired a watch assembly business based in Canton Ticino in Southern Switzerland. The new operation was subsequently registered as a subsidiary company under the name “Farone”.

Time marches on in watch manufacturing as it does everywhere else. In the early 1970s, the industry was shaken to its foundations by the arrival of quartz technology. The new quartz movements were far more accurate than their traditional mechanical counterparts, and the innovative technology also offered promising prospects of tapping into new markets and customer segments.
With typical dynamism, Ronda developed its first quartz watch movement as early as 1974. Sales proved sluggish in the first few years, though: the recession which followed the oil crisis of 1973 put a particularly severe dampener on European watch manufacturers’ interest in trusting and investing in the innovative new technology.

As new sales markets opened up in Asia, Ronda established its first branch office outside Switzerland – in Hong Kong – in 1972. Two years later the new operation started assembling pallet and pin-pallet movements. For strategic reasons, it was decided to refrain from producing quartz movements at the new Far East location. Swiss Parts quartz movements were assembled in Hong Kong and China from 1982 to the end of the 1990s.

When quartz movements finally broke through in the 1980s all over the world, the wristwatch advanced from a luxury item to an affordable fashion accessory. Ronda responded by making active efforts to further expand its workforce, and was able to recruit a number of new personnel from Alsace in neighbouring France. Over 50 buses a day were used to provide the local and regional commuter services required.

Company founder William Mosset died unexpectedly in 1985 at the age of 76. Virtually overnight, the management of the company passed to the children of his second marriage. His daughter Elisabeth and her husband Daniel were already working for Ronda, while his son Eric completed his studies at Zurich’s Federal Institute of Technology before joining the firm in 1989. When he did so, the second generation took the opportunity to revise the Executive Management team.

With steadily growing pressure on prices – initiated by Japan’s movement manufacturers – and further capacity needed anyway, Ronda transferred its Hong Kong and China assembly operations to Thailand, and founded a further subsidiary there in 1990 to manufacture individual components and assemble Swiss Parts movements.

Ronda steadily expanded its range of basic products in the course of the 1990s. In addition to a number of specialist items such as particularly small movements and those powered with lithium batteries (which run for over ten years), Ronda also launched the Powertech line of over a dozen movement products offering a wide range of functions.

Ronda was able to celebrate the 50th anniversary of its foundation in 1996 with a worldwide workforce of 1,000 personnel. The same year also saw the company become the first watch movement manufacturer in Europe to earn ISO 9001 certification. Today, compliance with these globally-recognized norms for a quality management system is to some extent a given for any company active in international markets.

Throughout the 1990s, Ronda made steady progress in penetrating the world’s markets with its Swiss Made and Swiss Parts movements. As well as expanding its capacities in Switzerland, the company also opened a substantially bigger manufacturing facility extending to some 9,000 square metres in Bangkok in 1998. The group’s Thai-based workforce grew to over 1,000 employees over the following years.

The launch of the Startech line in 2003 was a particularly revolutionary development. With their modular credentials, the new multifunction movements and chronographs offered customers unparallelled flexibility and diversity, and enabled Ronda to add several brands in the higher price segment to its customer base.        

Buoyed by favourable business trends and strong demand for top-class Swiss Made watch movements, Ronda was able to effect sizeable investments, including the further expansion in 2004 of its Lausen production facilities. Major investments were also made at the same time in the company’s customized CNC milling machines.

For strategic reasons – to secure its profile-turning capacity and further expand its expertise – Ronda acquired its long-standing partner Zwahlen SA in 2007. This latest subsidiary of the Ronda Group is based in Court in Canton Jura, Switzerland.

The technological developments planned for the Ronda Group’s operations in Thailand called for sizeable infrastructural facilities and a doubling of the existing production area. To this end, a third facility was added in 2009, providing a further 8,000 square metres of capacity.

Ronda developed and brought to market over 30 watch movements – almost all of them highly complex – between 2000 and 2010. So what can watch manufacturers look forward to next? With its new Startech 3500 series, the company launched a further line of movements with stopwatch functions in spring 2011. At 23.90 x 25.60 mm, these are the smallest chronographs to date in the product range. 

Apart from their size, the new layouts with counters at the 6-12 or the 6-9-12 positions offer customers particularly attractive opportunities to develop new looks when designing their future watch collections.

2013 sees the market launch of Ronda xtratech as a new product line. The Z60 is the first-ever Ronda 13¼‘‘‘ size calibre with chronograph function. With the xtratech the name says it all: a Swiss Made movement offering everything a chronograph needs. Not a feature more and not a feature less. In fact, the ideal product for watches in the fashion range, where demand runs high for useful functions at attractive prices.

As demand for mechanical watch movements continued to decline sharply, the company discontinued its production at the end of the 80s. After Ronda had strongly developed itself in various technologies and established a broad industrial basis, management decided to go back into the mechanical segment at the end of 2011. The 11½''' sized R150 caliber was introduced at “Baselworld 2016”, an in-house construction with three hands and date.

After 71 successful years in a challenging market, Ronda continues to look ahead and wants to secure its successful positioning as an independent family business for the future. In November 2017, Fabien Schirmer took over as the new CEO and continues to focus on customer proximity. The third generation at Ronda shall also be a good and reliable partner for watch manufacturers.

For the power supply, the solar movement launched in 2023 uses sunlight and stores the converted electrical energy. Since this line eliminates the need for frequent battery replacement, Solartech offers watch manufacturers an environmentally friendly option for timekeeping.