How does Jim view the life of the rich? What was the “Edwardian brigade”?

Could you please explain this paragraph?

“I hate to admit it, but I think I can understand how her Daddy must have felt when he came back from India, after all those years away. The old Edwardian brigade do make their brief little world look pretty tempting. All homemade cakes and croquet, bright ideas, bright uniforms. Always the same picture: high summer, the long days in the sun, slim volumes of verse, crisp linen, the smell of starch. What a romantic picture. Phoney too, of course. It must have rained sometimes. Still, even I regret it somehow, phoney or not. If you've no world of your own, it's rather pleasant to regret the passing of someone else's.”