I think it's important to point out that the use of "Chuck" as a pet form for "Charles" is fairly recent in historical terms, and that it started in the United States. So far I haven't been able to find any examples of Chuck used as a nickname for Charles before the 20th century, with the first reference showing any link between the two dating from 1913. If I find any earlier example I'll report it. :) [noted -ed]