をは confusion

I'm a bit confused by a sentence:

日本の着物は、平安時代に生まれました。この時代、男の人も女の人も、一番下に白い着物を着ました。「小袖」です。そして、その上に、袴をはきました。

That をは confuses me, though maybe just because my particle knowledge is one of my weak points. Is there a combination of those particles I just don't know yet? Should it maybe be:

そして、その上に、袴を履きました。

Or something (based on a quick Weblio search)?

Thanks for any help!

As you suspected, this is not a double particle but just を + the verb はく (履く), "to put on lower body" - applicable since a 袴 is a kind of skirt.

Related: 被る "かぶる", "to put on head" (hats, caps etc.)

Thanks!