From its first halting steps 50 years ago, Diethelm Travel Asia has grown to be one of the largest and most important inbound tourist operators in Asia, handling 500,000 leisure and business travellers every year.

While travel is the company's business, and Diethelm now employs some 700 people in nine countries, it still definitely calls Thailand home.

Diethelm Travel has grown up alongside the kingdom's tourism industry, from those far-off days in the late 1950s when visiting Thailand was still an exotic experience for only a handful of adventurous or rich travelers.

Diethelm Travel Asia traces its origins to an agreement signed in 1956 between Diethelm & Co's Shipping Department and Swissair, under which Diethelm agreed to act as the airline's agent in Thailand.

The first flight from Zurich arrived a year later, landing at Don Muang airport on 3 April. The event was marked with a set of postage stamps of the first flight cover, still on display at Diethelm's head office.

Many milestones in Diethelm Travel's history have been a success due to the vision and dedication of the company's staff, and those early days were no exception.

Initially, the company's first representative, Elio Wettstein, had planned to outsource travel and tour arrangements to local sightseeing companies. But Wettstein soon realised that the Diethelm Travel office could not be run profitably without selling foreign airline tickets and its own sightseeing tours too – which he started doing.

That ruffled some feathers among local Swissair management at the time and led to Diethelm Travel and Swissair going their separate ways. Diethelm Travel, in a familiar form to today, was born and took up residence in 1957, at 311 Suriwongse Road.

The first group of package travellers from Hotelplan Munich, numbering 65, landed in Thailand on 28 December 1959. In January 1960, a similar group, traveling on a Kuoni package, arrived.

Diethelm Travel thrived as word spread of the surprising and exotic splendours of Thailand and the friendliness of the Thai people. Arrivals grew steadily and Diethelm Travel's business flourished alongside it. Lasting friendships were formed between the company and Thailand, building on the long history of the Diethelm parent company in the kingdom.

One of the first major changes to Diethelm came in the 1970s with the formation of Diethelm Marketing Services.

While the name changed later, first in 1994 to Diethelm Tours, and then again to DITS Travel in 2001, and finally to the founding of the holding company Diethelm Travel Asia on 6 August 2002, Diethelm Travel's core business and vision have remained the same – servicing the needs of corporate and leisure travellers throughout the kingdom and beyond.

The company grew rapidly in the 1980s as Thai tourism boom took off in earnest. By 1987, the Government of Thailand's landmark "Visit Thailand Year", Diethelm handled 100,000 tourists for the first time. That built the basis for further expansion in the 1990s as tourist arrivals grew rapidly.

Diethelm Travel's first steps outside Thailand came in September 1991, when the company opened its office in Vientiane, Laos.

In October 1992, Diethelm Travel Cambodia opened its doors in Phnom Penh, the year the company was also voted Best Inbound Operator by TTG/PTN.

By 1993, Diethelm Travel had expanded in Laos from the capital to Luang Prabang and in Cambodia to Siem Reap.

Three years later, on 17 January 1996, Diethelm Travel Myanmar opened its doors with four offices throughout the country and the company was voted ‘Tour Operator of the Year’ by TravelAsia.

That same year, Diethelm Travel bought the Malaysian firm Semesta Travel and renamed it Diethelm Travel Malaysia.

Diethelm Travel opened its first office in China on 5 May 1998 – the first foreign-licensed tour operator to do so.

Vietnamese operations followed, with Diethelm Travel opening in Ho Chi Minh City and Hanoi on 4 May 1999. Also that year, Diethelm Events was launched as a continuation and expansion of the successful incentive department.

The expansion continues, as Diethelm Travel builds on the expertise and professionalism of all its people. In 2005, Diethelm Travel Bhutan was launched and in 2007 the company will open in India, a promising new area of growth.

Diethelm Travel Asia this year was also awarded ‘Asia's Leading Tour Operator’ at the prestigious World Travel Awards – the Oscars of the travel industry. It is a fitting tribute to Diethelm Travel Asia's undisputed position at the forefront of inbound tourism services in Southeast Asia.