When Julian Fellowes's friend's daughter was diagnosed with Type 1 diabetes, he held a fundraiser for research into the disease with a bidder promised to have a character named after him or her in the following season. The winner gave his son's name for Atticus Aldridge.
Edith mentions making a "trunk call" to London. During the first half of the 20th century in the UK, unlike in the US where local phone calls were unmetered and included in flat-rate billing, all calls were chargeable and the term trunk calling was adopted for long-distance calls. Initially a trunk call had to be booked in advance and a switchboard operator called the subscriber when the call set-up was completed.
Lady Rose (Lily James) is very involved in the cause of the Russian refugees and shows sympathy to the decayed nobility. In 2016, Lily James portrayed a Russian princess in the TV adaptation of War & Peace (2016)