How did st albans become a saint?

There seems to be no Saint Cadog, however there is Saint Cadoc of Llancarvan. Is this who you were referring to?

We do not know much aboyt Lydia except that she was apparently the first convert of St. Paul. Evidently she lived a life of heroic virtue as the early Christian community declared her to be a saint...

There are a number of saints named Isidore. Which saint were you referring to?

St. Thomas was one of Our Lord's 12 apostles. He preached the Gospel and eventually was martyred in India. The early Christians considered any person who died the death of a martyr to be a saint.

St. Michael the Archangel was created by God as a pure spirit long before the universe existed.