The natives are forcibly relocated to the planet's third moon, and some Earth species are introduced into Delta Magna III's marshy environment, including a number of squid. The Power of Kroll. 2148 Caven and his space pirates begins raiding argonite mining ships and taking their cargo. Milo Clancy is one of the hardest hit. The 2nd Doctor, Jamie and Zoe, with the aid of space mining pioneer Milo Clancy, break up Caven's ring of space pirates, and rescue Clancy's old partner.
Date is conjecture.
The Time Meddler. Although the Monk's notes say this happens 200 years after 1968, that would be during the Daleks' occupation of Earth from 2164 to 2174, so I'm pushing it back to shortly before the Dalek invasion. The Daleks bombard the Earth with meteorites infested with a plague which wipes out large portions of life. As a result, the Earth breaks up into much smaller communities which are unable to resist when a Dalek invasion force lands six months later. The Dalek Invasion of Earth.