From 1905, the Prussian administration combined around 100 passenger locomotives with a 2-4-0 wheel arrangement as P 1, some of which had been procured from the predecessor railways. Others were created after the founding of the state railways, with a second, more powerful series already being built according to standards. Thus, this type did not include identical locomotives, but only the locomotives of the Erfurt and Essen subdivisions. Similar locomotives from other directorates also became the P 2 and P 3 in 1905.

The most numerous model of the P 1 was the Ruhr-Sieg type, of which the Bergisch-Märkische Eisenbahn had 34 engines manufactured between 1873 and 1882. The Prussian State Railways had them built in the same form from 1885, and then in a more powerful, standardized form from 1889. A total of 90 of these types were built by 1891. A special feature of this type was the leading axle, which could be moved laterally thanks to a bissel frame, which, strictly speaking, led to the UIC axle formula 1'B. The drivers had a diameter of 1,580 mm and allowed a top speed of 70 km/h, which was sufficient for passenger trains at the time. Some engines had 1,730 mm wheels and could reach 90 km/h.

The first series had no brakes themselves, but only used the brakes of the tender. Only in the case of the locomotives built according to standard were the coupling wheels also braked. From 1885 there was a conversion to air brakes, which braked the tender and the rest of the train.

Although the procurement period for the P 1 lasted a long time, decommissioning began as early as the beginning of the twentieth century. Not a single one made it to be taken over by the Reichsbahn, the last ones were scrapped in 1926.