A relic is usually a physical object that has a direct association with a saint or with Our Lord. It can be a fragment of the saint's body, something the saint used in their lifetime or an object touched to the saint's body. 

A part of the saint's body is called a first-class relic, a second-class relic is something the saint used, and a third-class relic is some object touched to the saint's body.

At the Uganda Martyrs shrine Namugongo, there is a first class relic (bone) of St. Charles Lwanga in a glass attached to the front of the mahogany wood altar in the basilica.

However, when there is Mass at the Martyrs Lake, part of his (St. Charles Lwanga) relics that is kept at the archbishop’s chapel in Rubaga Catherial is brought with that of St. Mathias Mulumba, Bl. Daudi Okello and Ildo Irwa. 

Relics of the other Uganda Martyrs were either fed on by wild animals or buried at the Anglican Museum.