Who was the first European boxer to retire as an undefeated World Champion?

Jack McAuliffe (March 24, 1866 – November 5, 1937) was an Irish-American boxer who fought mostly out of Williamsburg, Brooklyn. Nicknamed "The Napoleon of the Ring," McAuliffe is one of only fifteen world boxing champions to retire without a loss. He was the first boxer to hold the World Lightweight championship from 1886 to 1893. He was the first European boxer to retire as an undefeated World Champion. He won 27 of 38 fights with the other 11 fights being drawn.

He was inducted into The Ring Boxing Hall of Fame in 1954 and the International Boxing Hall of Fame in 1995.

He made his first appearance as an amateur boxer in 1883. He turned professional soon after, fighting Jem Carney 78 rounds to a draw at Revere Beach, Massachusetts. He fought Billy Dacey for the lightweight championship and a $5,000 purse in 1888, and knocked him out in eleven rounds. He was known as a strong two-handed fighter with "cat-like" reflexes. In 1897 he successfully defended his title against Billy Myer in a highly publicized match at the Olympic Club, New Orleans.