English and French, from Old French & German, "nobility".
Alice is a contracted form of the Old German name Adalheidis as is Adelaide for which it is often a pet name.
Alicia and Alitia are Latinised versions of Alice which were used in old documents. Search on Alic* and Alit* to cater for Latin endings.
Elsie is sometimes used as a pet name for Alison, itself a derivative of Alice. A correspondent [JW] has noted an example where Alice and Elsie have been used for the same person although this is not thought [by us] to be a common pet name.