Unable to Change language to en-gb

Hi,

I would like to change the language my editor is using to 'en-gb'. However no matter what i set and where i set it it always stays using 'en'.

I have tried the following, but none of the settings seem to work. I am clearly missing something obvious but i can't seem to figure it out.

Any help would be greatly appreciated!

CKEDITOR.editorConfig = function( config ) {
	// Define changes to default configuration here. For example:
    config.language = 'en-gb';
    config.defaultLanguage = 'en-gb';
};

CKEDITOR.editorConfig = function( config ) {
	// Define changes to default configuration here. For example:
    config.language = 'en-gb';
};

<script>
CKEDITOR.replace('editor1', {
          defaultLanguage: 'en-gb', 
          language: 'en-gb' 
});
</script>

<script>
CKEDITOR.replace('editor1', {          
          language: 'en-gb'
});
</script>