The word 'thenceforward' is correct and usable in written English.
It means 'from that time onward', so it is usually used to indicate that something happened or changed at a certain point and continued after that. Example sentence: After that evening, they were thenceforward inseparable.
This Francia Media was partitioned by Lothar I in 855 between his sons: the elder of the two, Louis II, received Italy and the imperial title; his brother, Lothar, received the northern area, thenceforward known as Lothar's kingdom, or Lotharingia.
These dictated the concentric patterns of his Discs and Cosmic Circular Forms, which occupied him and his wife, Sonia, thenceforward.
Moving to Denver, Colorado, in 1906, she married Charles J. Walker, and thenceforward she was known as Madam C.J. Walker.
Within that period there were notable changes, not least the transfer of ownership of the work to the United States, but the seventh edition fixed the basic form of the encyclopaedia thenceforward.
Goths were also brought in by Constantine, to the number of 40,000, it is said, to help defend Constantinople in the latter part of his reign, and the palace guard was thenceforward composed mostly of Germans, from among whom a great many high army commands were filled.
In 1718, after the success of Oedipe, the first of his tragedies, he was acclaimed as the successor of the great classical dramatist Jean Racine and thenceforward adopted the name of Voltaire.
The British, though they had broken through the German defenses by October 5 and thenceforward had open country in front of them, could not pursue the Germans fast enough to endanger their withdrawal.
Thenceforward he seems to have been completely dominated by the queen, who must bear the chief blame for the court's subsequent political duplicity.
As each of the brothers assumed the title king, Castile and Aragon thenceforward were regarded as kingdoms.
Thenceforward, the islands were a bulwark to defend the Catalan coasts and a base from which trade and political expansion could be launched eastward.
Thenceforward he and his descendants John V (d. 1442), Francis I (d. 1450), Peter II (d. 1457), Arthur III (d. 1458; see Richemont, Arthur, constable de), and Francis II (d. 1488) constituted the House of Montfort as dukes of Brittany.
