St. Timothy was a convert of St. Paul who believed that he was intended for an evangelist. Timothy was ordained and at once became the beloved fellow-worker of St. Paul. Finally, he became the first bishop of Ephesus, and while there received the two Epistles which bear his name. In the year 97 he was beaten and stoned to death because of his opposition to idolatrous ceremonies, Pius IX in 1854 raised his feast to the rank of double.
(Source: Fr. Lasance, The New Roman Missal)