These panels, installed at the Mary's Chapel of the church, are the first testimony on independent Latvia to adorn the landmark, which was constructed in 1211.
On them is a stylized bonfire symbolizing a crucial event in recent Latvian history.
The 1991 Barricades was an event that saw people flow into the capitals of the Baltic states and erect makeshift barricades to protect strategic locations against Soviet troops that wanted to crush the Baltic nations' independence drive.
Just 27 years ago, people who wanted Latvia to be free kept warm with bonfires such as depicted in the glass.
The panels were designed by architect Krišs Zilgalvis, and its cost (around €140,000) was covered fully by the public.
"Each of the nine panels has special symbolic meaning. A flame in perpetual motion forms the basis of the design. The large vertical panels are dedicated to the historical regions of Latvia," he told Latvian Radio.
The glass design weighs almost a ton and could be described as a sculpture placed inside a window. It was designed by an international team of artists.
The panels change color depending on the angle and intensity of sunlight.
"It's like a diamond. Even though it's transparent, it includes the whole color spectrum and doesn't make any color the dominant one," said Zilgalvis.
Meanwhile Elijs Godiņš, dean of the Riga Cathedral, revealed that during the Barricades the church served as temporary lodging and hosted medical staff that helped the hundreds of thousands of people who took to the streets to help make independent Latvia a reality.
British glass makers Arup also helped the project, as the UK embassy shows in a video about the design and planning aspects of the initiative.
To mark the 1991 #Barricade events a special glass sculpture was created in the window of the Riga Dome cathedral by artists Kriss Zilgalvis and Dzintars Zilgalvis in cooperation with the UK company @ArupGroup— UK in Latvia (@UKinLatvia) January 20, 2018
The artists told us more about the creative process and the artwork. pic.twitter.com/4ObNvk3bOc