In the 15th century, the town of Diessenhofen became mostly independent and took over the jurisdiction of Schlatt.

The St Nicholas Chapel, which existed from 1316 until 1812, belonged to Stammheim parish (today Oberstammheim and Unterstammheim).

Though the Protestant Reformation of 1529 created an independent parish of Schlatt, it declined until it was abolished in 1769.

[3] Schlatt has an area, as of 2009[update], of 15.53 square kilometers (6.00 sq mi).

[5] Schlatt also shares an international border on the river Rhine with the German municipality of Büsingen am Hochrhein which is an enclave entirely surrounded by Swiss territory.

[7] Most of the population (as of 2000[update]) speaks German (95.8%), with French being second most common ( 0.7%) and Italian being third ( 0.7%).

[7] The age distribution, as of 2009[update], in Schlatt is; 159 children or 9.9% of the population are between 0 and 9 years old and 235 teenagers or 14.7% are between 10 and 19.

[12] In the 2007 federal election the most popular party was the SVP which received 54.05% of the vote.

In the federal election, a total of 575 votes were cast, and the voter turnout was 52.0%.

[13] The historical population of the former municipality of Mett-Oberschlatt (Unterschlatt is not listed) and the total population of the combined municipality (both before and after the actual merger) is given in the following table:[3][5][14] The former Poor Clares Monastery of Paradies in Unterschlatt, the Schaarenwald (a Bronze Age settlement, Roman watchtower and early modern fortification) and the Double Farm House are listed as Swiss heritage sites of national significance.

The entire hamlet of Dickihof and Paradies Monastery are included in the Inventory of Swiss Heritage Sites.

[8] From the 2000 census[update], 261 or 17.6% were Roman Catholic, while 924 or 62.2% belonged to the Swiss Reformed Church.