The Second Doctor was portrayed by character actor Patrick Troughton from 1966-1969.

Season Four (1966-1967)

• The Power of the Daleks
• The Highlanders
• The Underwater Menace
• The Moonbase
• The Macra Terror
• The Faceless Ones
• The Evil of the Daleks

Season Five (1967-1968)

• The Tomb of the Cybermen
• The Abominable Snowmen
• The Ice Warriors
• The Enemy of the World
• The Web of Fear
• Fury from the Deep
• The Wheel In Space

Season Six (1968-69)

• The Dominators
• The Mind Robber
• The Invasion
• The Krotons
• The Seeds of Death
• The Space Pirates
• The War Games

Source of inspiration and material: Wikipedia & BBC