A number of Sylvia Plath’s letters and personal items – including her wedding ring, a captioned photo album and her drawings of Ted Hughes – are to be sold at Sotheby’s.

Dr Gabriel Heaton, Sotheby’s English literature and historical manuscripts specialist, said the sale, which opens on 9 July, reveals Plath’s creative development, her love for Hughes and her sense of humour.

The 32 letters are made up of those written to Hughes in October 1956 and others she sent to her in-laws up until 1961.

Heaton said: “Here you have the beginning of this relationship when she is deeply, deeply in love. She’s wonderfully excited about their union and about the future. But also you get such a strong sense of their literary collaboration and how they’re working together and thinking together.”

The letters also include Plath encouraging the then mostly unknown Hughes to enter a prestigious s poetry contest. Hughes went on to win the competition in 1957, with a collection that included The Hawk in the Rain, and it helped launch his career.

A family photo album, captioned by Plath which records her and Hughes’s road trip across America.  covers the period from after their honeymoon, to their final year in Devon, and is described by Heaton as an “intimate, domestic photo album”.

“There are lots of photographs of the time they spent on the road trip in America which is very heavily recalled by Ted Hughes in Birthday Letters, for example. In terms of a portrait of their marriage, it’s really a very beautiful thing,” he said.

There are also a set of tarot cards, given as a gift to Plath by Hughes, an Egyptian figurine given by Hughes to Plath on their honeymoon and drawings of Hughes by Plath as the pair honeymooned in Benidorm.

The humorous side of Plath’s personality is also on show. There are letters which reveal her contempt for life at Cambridge, and a cartoon that shows her disdain for domestic life with the poet drawing a scene depicting herself as a maid attacking a dinner guest with an axe.

Plath killed herself in 1963, not long after her marriage to Hughes broke down.