Our ancestors are coming from the province Fujian in China. Fujian means "Happy Establishment".
Unfortunately, nobody knows about the place where our first ancestor Gan Hwan came from. The main  towns of Fujian are Xiamen (Amoy), Zhangzhou, Quanzhou, Anhai, Shishi, Tong'an and Jimei.
Fujian is situated in the east coast of China, directly across Taiwan. The majority of the population are Han Chinese.
We don't know, why Gan Hwan left China for Indonesia; did he leave his wife in China, did he have brothers and sisters and where are their descendants?
My parents started to look for Gan family members in Fujian during a business trip of my father in the 80's.
A television company accompanied them and they found a village near Xiamen where most of the families have the surname Gan. The time was too limited so my parents couldn't find out more about them.

Some family members suspect that our ancestors left China during the opium war and that they were poor people desperately looking for a new place to live in peace.

Since our ancestors came more than 100 years ago, in Indonesia they are called "Peranakan" which means that they are Chinese people who already live in Indonesia for many generations.
The so called "Totok" Chinese are those who just immigrated to Indonesia from China or whose parents were born in China.
While Totok Chinese still follow Chinese traditions, still speak Chinese and are often Buddhists or "Confucianists", most of the Peranakan Chinese don't understand or speak Chinese anymore; they are more influenced by the Dutch culture and are mostly Christians. Very few Peranakan Chinese even converted to Islam like the majority of native Indonesians.

Most of our relatives now live in Holland, Germany and USA (besides Indonesia).
I don't think that any of my relatives still know how to speak "Min Chinese" (also Fujian dialect, Fukkienese, or in Indonesia known as Hokkian), the language of our ancestors.
It is unclear which dialect they spoke because there are three different Fujian dialects, which are Fuzhou dialect in the north, Xiamen dialect in the south and Henghua dialect in the middle of Fujian.
The population in Central Java (like Purbolinggo where our family comes from) speaks Javanese language besides the main language bahasa Indonesia.
Many relatives of my generation who moved to Europe or USA don't even speak Indonesian language anymore.