4 May 1912: birth of Peter Bathurst, who played Hensell in The Power of the Daleks (Second Doctor, 1966-67) and the awful Chinn in The Claws of Axos (Third Doctor, 1971).
4 May 1959: birth of Anthony Calf, who played the Squire's son Charles in The Visitation (Fifth Doctor, 1982), his first professional acting role, and Colonel Godsacre in Empress of Mars (Twelfth Doctor, 2017).
ii) broadcast anniversaries
4 May 1968: broadcast of second episode of The Wheel in Space; first appearance of Wendy Padbury as Zoe. The Doctor is incapacitated and Jamie makes a new friend.
4 May 1974: broadcast of first episode of Planet of the Spiders. The Doctor investigates a clairvoyant; Mike Yates and Sarah Jane investigate a meditation cult under the control of spiders.
4 May 2013: broadcast of The Crimson Horror. In 1893, Jenny infiltrates Mrs Winifred Gillyflower's community of Sweetville in Yorkshire to find what has happened to the Doctor.