The class 429 passenger locomotive of the kkStB was introduced in 1909 after superheater technology had established itself in Austria. It was developed from the 2-6-2 class 329 and looked very similar to that. The smokebox had been extended at the cost of the boiler tubes to create enough space for the superheater header.

The first 57 locomotives, numbered in the 429.01 range, had slide valves which led to some problems while running on superheated steam. So another 126, numbered from 429.100, were built with piston valves. Also the Südbahn ordered six of this Type. While these were all two-cylinder compounds, a two-cylinder simple variant was built as 429.900. These reached the highest number with 197 built until 1918.

They quickly became spread over all Austria-Hungary. After the war, a large number came to several countries. So they became ČSD class 354.7, FS class 688, JDŽ class 106, PKP class Ol12 and MÁV class 323.9. The ČSD also rebuilt all their 84 compounds into simples, what made 152 together with the original 429.9. Most got two domes with an interconnecting pipe and were used until 1967.