[Janet MacD]

I recognize Doctor Sun Yat-Sen! Toronto installed a statue of him in a park near our neighbourhood.

Google says:

• This is a postage stamp from the Republic of China featuring a portrait of Dr. Sun Yat-sen.
  
• The stamp is part of a series featuring Dr. Sun Yat-sen, who is considered the founding father of the Republic of China.
  

There is a great Wikipedia article on the various series of stamps China issued to honour the doctor:

https://en.wikipedia.org/wiki/Sun_Yat-sen_stamps

Your stamp is from what Stanley Gibbons calls the 12th Definitive Series. It was the first series to use the nice clean - dare I say modern - portrait design. Earlier series framed the portrait. It was issued during a period of high inflation. In August 1948 the Chinese National Currency was replaced by the Gold Yuan. The stamps in the series have values between 1 and 1000 yuan. Later printings had top values of 100,000 and 500,000. In April 1949 the Gold Yuan collapsed. The replacement currency was the Silver Yuan. The definitives printed with values from 1 to 500 cents in the new currency were the last Doctor Sun stamps issued before China split.

There is a lot of information online about Dr Sun’s political accomplishments, and his work to modernize China. He is credited with writing the national anthem of the Republic of China - The Three Principles of the People.

Lovely stamp!