Good to know about Troisdorf

The name "Troisdorf"

In the founding charters of Michaelsberg Abbey, situated above Siegburg, Troisdorf is named "Truhtesdorf".
The word Truth is derived from the first name Trutmar or from the Gothic word druth, meaning "the village of a follower of the king". The suffixes "dorf" (village) and "heim" (home) are among the oldest place names.

There are no archaeological finds from this period (500 to 800 A.D.). The name of the former knights castle, "Wissem", also indicates early settlement, as the suffix "heim" can be found in the different forms of "Wissem": "Wishem", "Wiesheim" and "Wisshem".

The first documentary evidence is now accepted to be the genuine property deed of Siegburg Abbey dated 1075, which mentions the church at "Truhtesdorf" and a local estate.

Spelling of the name "Troisdorf"

The spelling of the name "Troisdorf" has changed frequently since 1066:

The "oi" and "oy" forms appear in 1318 and 1323 and last until 1573. This form then disappeared until 1772.
From 1789, it was spelt as Droisdorf/Troisdorf, but only as Troisdorf after 1815.

In 1901 the commission for spelling reform in Germany stipulated that "oi" must be pronounced like the "oo" in standard German, but the word must continue to be written with "oi" to indicate the elongation of the letter "o".
The letter "i" only comes after the letter "o" to elongate it.

This can also be seen in Haus Broich, near Roisdorf, and in other words.
It does not affect proper names, such as Froitzheim.