The Barony of Tir-y-Don's lands cover the middle peninsulas of Virginia including the cities of Hampton, Newport News, Poquoson, Yorktown, Gloucester, and Williamsburg. It is Atlantia's fifth Barony and dates from Atlantia's time as a Principality
The first SCA activities within what became Tir-y-Don occurred in 1975 (AS IX) with its first event on March 1st. Tir-y-don became an official Canton within the East Kingdom in July of 1976. Five years later it became a Barony on April 25, 1981, a week before Atlantia became its own Kingdom on May 2, 1981. For more details see Tir-y-Don's history page on its website.
Tir-y-Don's website is available at http://tirydon.atlantia.sca.org.