116v

[arca_libraria]

The charter (the second one down in your post) is using the crosses to indicate each person who witnessed the grant of land being made. The part of the charter with all of the crosses is known as the witness list/subscription list and each person there is saying “I Leofric a duke [witnessed this]”. Gifts of land were recorded publicly in the early middle ages and the witnesses could theoretically be called upon to help if the details of the grant were ever disputed.

You can see another security feature, known as a chirograph, at the bottom of the image. Some charters were copied twice onto a single sheet of parchment, one copy for the giver, one copy for the receiver. The scribe would write a big word, usually a variant of CHIROGRADUM in between the two copies and then cut the page in half - this was to stop someone making another copy of the charter and changing the terms - if there was any dispute then the two halves would have to be produced and checked to see if they matched up. 

In some charters all of the crosses are very different, which suggests that although a single scribe wrote all of the text including the names of the witnesses, each witness made their own cross. In a lot of early medieval charters though all of the crosses are probably by the same scribe and the crosses are a stylistic convention and are part of the way the charter-scribe recorded who was present.