In 1839 the first Henley Regatta was held on the Thames, and the town of Henley-on-Thames has been home to the Royal Regatta ever since. The rowers there made a collarless undervest their standard uniform, because the placket gave them ventilation and there was no collar to flap. That is the whole origin story of the henley shirt: a piece of underwear that walked out of the drawer and onto a riverbank.

A henley is defined by a banded collar and a placket of two or more buttons, and the best ones still read like a t-shirt with a neckline you can open. There is even a tradition that the losing crew handed their shirts to the winners, which is how a regatta souvenir turned into a wardrobe habit. It is the top you reach for under a coat in October.

The long-sleeve version is the easiest place to begin. The Cotton Citizen Verona in jet black is a ribbed jersey with a partial button front, made in the USA, and it works under a blazer or alone with trousers. The Michael Lauren Tahoe has thumbhole cuffs in a faded vintage black, which I would wear with a leather skirt and ankle boots. The Lovers and Friends Larisa in mushroom is a soft rib knit that suits a camel coat. The Abercrombie and Fitch cotton henley in heather gray and the Quince micro-rib in soft white are plainer ones I would layer under overalls or a denim jacket.

The Great Shrunken Henley in red and navy stripe is the playful pick, a short, snug cotton jersey that looks best with high-waisted jeans. One tip before you buy: button the placket in the mirror and check that it lies flat across your chest instead of pulling open. If it gapes sitting down, size up.

Thermal knit is where the henley goes back to its underwear roots. The shirt began as a nineteenth-century undergarment, and the waffle texture still looks like something that should be worn close to the skin on a cold morning.

The Free People Montreal in ivory is the slouchy one, oversized, with dropped shoulders, a scoop neck and a distressed button placket. I would wear it over leggings with chunky socks and clogs. The Citizens of Humanity Drea in charcoal is lighter and tapers at the waist, so it tucks into jeans without bulk. The EDIKTED Baila in black is relaxed and long-sleeved, a good one under a slip dress when the weather turns. The Pact thermal pullover in dark gray has a V-neck and organic cotton, which I would put under a shirt jacket.

If you want a little more detail, the Lucky Brand in burgundy has an embroidered yoke, and the Michael Stars Regan comes in a cream waffle knit with dainty posies and a snap half placket. The Eileen Fisher high-collar version is a smooth-inside double knit in black, the quiet pick for work.

Before you commit, press the fabric against your forearm and look at the waffle pattern: a deep, even texture holds its shape, while a flat one can go limp at the cuff. What I would skip: the floral version if your closet is mostly solids, because it will not mix as easily as the plain colors.

Fit is the whole conversation with a ribbed henley. The knit hugs the body, so the placket sits just right or looks stretched, and there is not much in between.

The LNA Dalston in black is a fitted ribbed jersey made in the USA, which I would wear under a long open cardigan. The Good American ribbed henley in ivory has a snap gusset, so it stays put when you tuck it in. The 525 America Emmeline in black combo is a layered rib henley in slinky jersey with a quarter button closure, and it is the one for a night out with satin trousers. The Negative Underwear Whipped Henley in heather gray is micromodal with a partial snap front, with a loungewear mood that is exactly the appeal.

Year of Ours makes a ribbed henley tee in a heather gray and white stripe, made in the USA with a crew neck, and I would pair it with straight jeans and loafers. The Veronica Beard Dekalb in green has puffed shoulders and a V-neck, which dresses it up for dinner. The Threads 4 Thought Akia is a feather-rib in black, and the Uniqlo ribbed henley neck tee in light gray is the simple layering piece, offered in eight colors.

Test it by raising your arms. The hem should not ride past your waist, and the buttons should not pull. What I would skip: a snug rib in a very thin fabric if you plan to wear it alone, since it shows every seam of what is underneath.

A short sleeve changes the henley completely. It stops being a base layer and becomes a warm-weather top, which also makes it useful for a mild October afternoon with a jacket on top.

The Leset Nando in black is a fitted short-sleeve tee in stretch cotton jersey, made in the USA, and it goes with anything with a high waist. The Vince elbow-sleeve henley in off-white has gold-tone buttons and a ribbed jersey, a lovely thing under a navy blazer. The Citizens of Humanity Nali has a quartz stripe and front buttons, which I would wear with white jeans. The Cou Cou Intimates Baby Henley is a white pointelle knit with a button front, made in Portugal of organic cotton, and it reads like a vintage nightgown top.

For cropped styles, the EDIKTED Teddy is a boxy waffle knit crop in heather gray with a snap half placket, and the Florence by Mills ribbed crop in white is cut for high-rise trousers. The COS ribbed henley in white has tonal buttons and a poplin placket, the polished one. And the Polo Ralph Lauren short-sleeve henley sweater in clubhouse cream is a nod to the brand credited with bringing the henley into casual wear in the 1970s.

Check the length against your waistband: a crop should land at the top of your trousers, not hover above them. What I would skip: a cropped henley with low-rise bottoms, because the placket then points at nothing.

Wool is where the henley meets the sweater drawer, and the placket becomes a small, useful detail instead of the main idea.

The Abercrombie and Fitch merino-wool blend in cream heather has a buttoned neckline and ribbed hem and cuffs, which I would wear with a corduroy skirt. The Treasure and Bond wool and cashmere henley in oatmeal has raglan sleeves, pointelle at the shoulders and a partial button placket, and it is the one I would pack for a long weekend away. The Favorite Daughter Lush Lounge in mocha is a lightweight blend of wool, nylon and cashmere with a quarter button closure, and the SABLYN Maeve is an open knit of cotton, silk and cashmere in gardenia and pink sand, which should be dry cleaned.

For texture there are the Lovers and Friends Mara in ivory open stitch and the Adanola Volume Sleeve in marshmallow white, with big sleeves that look good under a trench. The 525 America snap-front sweater in oxblood is the deep fall color, and the ELLE Collection fuzzy knit in brown has crystal-style buttons that make it feel dressier than the others.

A quick test: pinch the knit at the elbow and let go. If it springs back, it will hold up. What I would skip: a fuzzy or open knit under a structured coat that rubs, since the fibers will pill at the seams.

Decide what the shirt is for. If it is a layer, take a thermal waffle or a ribbed long sleeve. If it replaces a t-shirt, take the short sleeve. If it is a sweater, go with the wool.

Then check the placket, the fit across the chest and the cuffs, in that order. Buy one in a color you already wear, then add a second in a texture you do not own.

It still amazes me that a garment from a rowing town in 1839 ended up as the thing I would grab on a cold morning. If you want to keep browsing, I also put together Rails and Henley Tops.