Rolex started of as more of a watch assembler than maker. The company opened back in 1905 by 24 year old immigrant
Hans Wilsdorf and his English brother in law Alfred Davis. The firm used to import Swiss watch parts and fit them into English watch cases. Three years later the business partners decided to make the watches themselves and opened an office in Switzerland because that’s where the majority of skilled watch makers were.
Due to incredible high taxes in Britain they finally closed down their British office in 1919 and have remained in Switzerland ever since.