The Ducaet Estate

The Ducaet Estate is located in Kerkhoven, a hamlet of the city of Lommel in the province of Limburg, Belgium.
The lands of the Ducaet domain are registered with the services of the Land Registry as "De Ducaet" ("piece erff geleege the bet venne genaamt de ducaet, west of the vivious course, in 1774, HP 33, 73R, scissors forest called Ducat, 1834, Van Breugel, 22 min"). The naming of the domain has its origins in the cash handling when purchasing the domain in 1774. The purchase price was paid with (gold) ducats.
The coins with which the purchase price of the domain was settled in 1774, originate from Italy.
When in 1284 Doge (Doge i.e. Duke) Giovanni Dandolo, the 48th Duke of Venice, had a new gold coin minted under the name of Zecchino , it was given the following description:
" Sit tibi Christe datus , quem tu regis iste ducatus ." ("This duchy, which you reign, be ordained to you, Christ.").
This last word finally became the name of the gold piece: " ducat "
It weighed 3.5 grams with a content of more than 23 1/2 carats.
This ducat was in circulation as a coin for quite some time, it was minted from 1284 until the end of the Venetian Republic in 1797, so over 500 years. Due to the high (.999) purity of the gold used  and the long mint time, this coin became a standard for world trade.

Taken from "From Vriesput to Little Germany - Eight centuries of Lommel place names", Victor Mennen, 1992, Publications of the association Kempenland Museum.