John Crucefix was made free in the Clockmakers Company in 1712, as a Brother, implying he too learned his trade elsewhere than in the Company. He is believed to have started making clocks as early as 1699, and his latst date to about 1730. His two sons, Jean and Pierre, were apprenticed through the Clockmakers' Company as plain John and Peter. John senior’s brother Robert was also a clock-maker. Of the few John Crucefix's clocks that survive, most are thirty-hour lantern clocks.