Queen Victoria and Prince Albert

Queen Victoria (1819-1901) married her first cousin, Prince Albert (1819-1861) of Saxe-Coburg and Gotha, on February 10, 1840 at St James's Palace.  Their nine children married into royal and noble families across the continent, tying them together and earning her the sobriquet "the grandmother of Europe". After Albert's death in 1861, Victoria plunged into deep mourning and avoided public appearances.  Her reign of 63 years and seven months is known as the Victorian era and is the second longest of any British monarch.  She was surpassed by her great-great-granddaughter Elizabeth II. 

Victoria is an eight part British drama television series that premiered on August 28, 2016 on ITV.  RadioTimes has an article comparing the TV series to the real life couple:

"These days, marrying cousins is sometimes frowned upon but in the UK it is perfectly legal and the British royal family have been doing it for hundreds of years in order to ensure strong alliances and allegiances.

In this week's episode of the ITV drama the relationship between the cousins is strained at first, with neither overly keen to get married in accordance with their parents' wishes and Victoria expressing distaste at Albert's personality.

However, in real life it doesn't seem like this was the case. Certainly, Victoria appeared to think Albert was made for her from the beginning, having met him in 1836 a year before she ascended to the throne (unlike in the TV series where it's implied the pair haven't seen each other since they were much younger).

Writing in her diary after their first meeting, she noted some of their physical similarities and was clear about her attraction to him."

Update (December 4, 2022): On September 24th, History of Yesterday had an article about this royal couple: Why Did Queen Victoria Marry Her Cousin?