If you lived in England in 1750-1900 and you wanted to be seen being wealthy, you did it in a landau. The landau was a fancy carriage, pulled by four horses, generally with two passenger benches facing each other, plus the driver's seat up front. There might also be a groom's seat mounted behind the carriage. The defining feature of the landau was that it was fully convertible. When the folding hoods were up the landau provided full protection from the elements, but when they were down the low sides of the landau were perfect for parading your finery through the park. Many landaus even had retractable glass windows in the doors, to turn the half door into a full door when the tops were up.
The landau was a nicer carriage than the more common brougham, but more useful than an open barouche or phaeton, as it was was comfortable even in the cold or rain. Even so, it was not particularity well suited to long journeys or quick outings, so rarely would someone own just a landau. Driving one indicated the you had a sizable carriage house back at the estate.
There were a number of different types of landau, but the most common were the landaulet, a shorted, two-seater version of the landau, the Shelborne Landau, which had a traditional, angular bottom, the Canoe Landau (or Sefton Landau), which had a gracefully curving bottom.
The landau is less familiar to us than the Town Coach (the traditional princess carriage, which was not convertible) or the barouche, which only had a half hood, and is often found providing carriage rides to tourists. However, the landau was more of a staple in wealthy households than either of these, and it remains somewhat common in those few modern contexts where horse-drawn carriages are still called for, perhaps more so in the UK than in America.
The landau was named after the German city of Landau where the design originated, and where most of the earlier landaus were imported from. It is pronounced 'lan-daw'. It wasn't until the 1830s that Lord, Hopkinson, coachmakers started producing these carriages in England.