This chapter examines word order variation and change in the high CP-domain of Hungarian embedded clauses containing the finite subordinating C head hogy ‘that’. It is argued that the complementizer hogy developed from an operator of the same morphophonological form, meaning ‘how’, and that its grammaticalization path develops in two steps. In addition to the change from an operator, located in a specifier, into a C head (specifier-to-head reanalysis), the fully grammaticalized complementizer hogy also changed its relative position on the CP-periphery, ultimately occupying the higher of two C head positions (upward reanalysis). Other complementizers that could co-occur with hogy in Old Hungarian eventually underwent similar reanalysis processes. Hence the possibility of accommodating two separate C heads in the left periphery was lost and variation in the relative position of complementizers was replaced by a fixed order.
