On a system level, there was never a movement of simplification until the early 20th century. Chinese characters developed from less refined writing techniques and simpler shapes to more standardised writing styles and characters with more complex structures. This is because simple shapes have two (possibly related) problems:
- They're too easy to confuse with other simple shapes;
- You can only make so many simple shapes, and there isn't enough of them to represent the basic units of the language.
Chinese characters thus naturally piled on more components to existing characters to make enough distinguishable characters to represent the language sufficiently. Simplifications are therefore relatively rare, and are only one kind of process of how characters have changed in general. Exclusive simplifications (which make a former character obsolete) are close to nonexistent.
This being said, one can sometimes find individual characters that were known to be unambiguously simplified at one stage from a previously more complex character. I'll show two examples, the first which people would be more familiar with but doesn't really fulfil the criterion
earliest, the second to actually fulfil this criterion (in an approximate sense).
「与」is ultimately a corruption of「牙」. As is already known,「与」is a simplified variant of「與」.
「與」(Baxter-Sagart OC: /*m-q(r)aʔ/) is comprised of semantic four hands「𠂇𠂇又又」and phonetic「牙」(/*m-ɢˤ<r>a/).
「牙」was a common phonetic loan for「與」in the Warring States period to the Han Dynasty. Over time,「牙」suffered some shape changes into「与」inside the character「與」(changes outside as a stand-alone character resulted into the modern form of「牙」instead). This leads on to the Shuowen erroneously describing「与」as a component of「與」, and「与」as a separate character from「牙」:
The current form of「与」is a result of an incorrect shape analysis from Shuowen (hence why using Shuowen to demonstrate glyph evolution without checking modern publications on the subject can lead to serious errors), and is really just「與」, inclusive of its corrupted「牙」component, stripped of its four hands「𠂇𠂇又又」.
As mentioned earlier, Chinese characters piled on more components to existing characters to make enough distinguishable characters to represent the language sufficiently. 《荊門郭店楚簡》語叢3.9 is an example where「牙」is used as a phonetic loan or rebus for「與」. What happens when you start using phonetic loan characters? You need another character to represent the original meaning, here demonstrated by piling on more components on to「牙」to distinguish its uses.
「𤘈」is a precursor to「齖」, which has even more components; what looks like「臼」in this character is a shape-approximation of the same picture which forms the bottom part of「齒」.
Exclusively found in Shang Dynasty oracle bones, the simplified form was dropped relatively quickly.
「伐」(to behead > kill > attack) is a picture of a person「人」and a dagger-axe「戈」, where earlier forms deliberately drew the blade of「戈」across the neck of「人」, emphasising the meaning to behead.
In the simplified form (佚328 and others), most of the shape of「戈」is removed, with only the blade across the neck remaining. The following is a text sample to demonstrate the usage of this shape.
The following text contains both「伐」and its reduced form「⿻人一」, both shown in red. Reading order given by circled numbers ①—⑭.
(Jiǎwǔ [甲午] day divination [卜]) Oracle Zhēng [爭] asked [貞]:
- "On the day of yǐwèi [乙未] in the period of yì [翌], sacrifice [use, 用] a Qiāng person?"
- (Divined a positive result) "Confirm sacrifice [用]."
- "That [之] day [日] is cloudy/overcast [陰]".
(Jiǎwǔ day divination) Oracle Zhēng asked:
- "On the day of yǐwèi in the period of yì, don't [勿] sacrifice a Qiāng person?"
- "On the day of yǐwèi in the period of yì, sacrifice a Qiāng person?"
(Yǐwèi day divination) Oracle Bīn [𡧊] asked:
- "Will the farmers [grass cutters for animal feeding, 芻] be brought over [以] from the land of Wǔ [⿱戈止]?"
- "Will the farmers be brought over from the land of Wǔ?"
- "Will the farmers not [弗] be brought over from the land of Wǔ?"
- "To return favours [侑] to [于] our ancestor Tang [唐子], shall we conduct a beheading [伐] ritual?"
- "Beckon [呼] someone to grab [取] a sacrificial person [⿱子止] for a beheading [⿻人一] ritual?"
- "Conduct a bonfire [燎] ritual for the regional gods [社]?"
- "Return favours for our ancestor King Fùyǐ [父乙]?"
- "The king [王] had a dream [夢], will there be disaster [禍]?"
- "Will there not [不] be disaster?"
- "Will the king suffer an eye [目] disease [疒]?"
- "Will the king not suffer an eye disease?"