- 1930 - Omega and Tissot joined together to form SSIH group. Lemania, Lanco, Cortebert, Rayville, Marc Favre, and Hamilton were added over the years.
- 1971 - E.S.T.H. (Economic Swiss Time Holding) was integrated with with the Billiguhr brands AGON, Buler, Continental and Ferex. With the advent of electronic watches in the "quartz crisis of the 1970s, mechanical watch revenues of the SSIH group fell massively.
- 1980 - Management consultant Nicolas G. Hayek was commissioned by creditor banks to restructure the group. This provided the impetus for the merger of SSIH with the competing companies in the ASUAG group. This company became known as SMH. Crucial to its survival, and subsequently a great success, was the launch of the Swatch at Trenduhr.
- 1998 - SMH was renamed Swatch Group.