N is for... Nixon, President

In the weeks running up to the first manned space mission to the Moon - Apollo 11 - in 1969, President Richard Milhous Nixon began receiving mysterious telephone messages from a child.

He thought the caller to be a boy, named Jefferson Adams Hamilton. Suspecting his own secret service to be involved, Nixon called upon ex-FBI operative Canton Delaware III to investigate, being now an independent agent. The TARDIS materialised invisibly in the White House's Oval Office but the Doctor was spotted and captured. He and his companions agreed to assist Canton. He identified the child as a girl, with the names corresponding to a junction of streets named after ex-Presidents. The only location where such roads met was in Florida, close to Cape Kennedy where the Moon mission was being prepared. The Doctor was later arrested, accused of attempting to sabotage the space capsule, and Nixon was brought in the TARDIS by River Song and Rory Williams to extricate him. 

The President also assisted the Doctor and his companions at Area 51 where they were tricking the alien Silents into thinking that they had been either captured or killed.

Because of the mysterious phone calls which had triggered these events, the Doctor encouraged the President to record all of his calls - something which would eventually contribute to his downfall during the Watergate scandal.

In December 1999, the newly regenerated Eighth Doctor found a mask of the one-time POTUS in a hospital locker whilst searching for some clothes.

Played by: Stuart Milligan. Appearances: The Impossible Astronaut / Day of the Moon (2011).

• From its second season onwards, Milligan took over from Anthony Head as the American magician Adam Klaus in the comedy crime series Jonathan Creek.
• In 2009 he voiced the character Colonel Stark in the animated Doctor Who story "Dreamland". He has also featured on Big Finish audio productions.
• Milligan played another POTUS in the movie Wonder Woman: 1984.
• Nixon (1913 - 1994) was the 37th President of the United States. After successes such as becoming the first US leader to visit Communist China, his time in office came to an ignominious end when he became involved in political scandal when Democratic Party offices in the Watergate Building were burgled by men associated with his re-election campaign.