This vintage postcard features a print of a drawing of Windsor castle across the river Thames with swans in the foreground. Some of the image is picked out in yellow. On the bottom left corner are the words "Ent Stat Hall" and the bottom right has "Windsor".
On the back of the postcard is a handwritten message in ink addressed to Mrs Ison, of Kneesworth Street, Royston in Hertfordshire. The message (which is devoid of punctuation) reads;
"Many thanks for letter also for what have done quite forgot the [?] birthday so sorry, leave box till Sunday shall look forward for sunday with love to all [name] hope it will not be wet."
The postmark is partly missing but the year seems to be 1909, although it's hard to see which King's face is on the stamp as the postmark obscures it.