This sounds like Mystic Knights of Tir Na Nog, I also watched this show as a kid, in the same time period. Maybe this is the one you saw

This sounds like Mystic Knights of Tir Na Nog, I also watched this show as a kid, in the same time period (1998-1999).

Queen Maeve of Temra seeks to conquer the peaceful kingdom of Kells and enlists the evil fairy Mider, who gives her the mystical Rune Stone allowing Maeve to use sorcery, most often to create ogres and evil giants, whom she sends to wreak havoc. When King Conchobar of Kells seeks a way to protect his kingdom, protagonist Rohan, a druid's apprentice, goes in search of the prophesied hero 'Draganta', with his friend the reformed thief Angus. Later joined by the foreign Prince Ivar, and Conchobar's daughter, Princess Deirdre, they are drawn into Tir Na Nóg, whose king Fin Varra puts the group through various tests to determine their worthiness. The heroes having passed these tests, King Fin Varra gives them certain weapons granting control of the Classical Elements Fire, Air, Earth, and Water. Thereafter the four overcome Mider's 'Evil Sentinels' (recurring villains in the series) to capture corresponding suits of armor, and oppose the various monsters created by Maeve, assisted by the winged fairy 'Aideen'. Subsequently, Rohan gains a new partner in Pyre the dragon, who later identifies Rohan as Draganta.