The Belgian stamps from the period 1869 to 1897 are particularly valuable and highly prized by collectors, especially the stamps depicting King Leopold II. Here are some of the most important and valuable stamps from this period:

1. **Postage stamp of 1869**: This was one of the first stamps with the portrait of Leopold II. The design features a profile of the king with a wreath all around. These stamps are extremely rare and can fetch high prices at auction, especially if they are in excellent condition.

2. **Postage stamp of 1870**: This stamp again shows Leopold II and was issued in different colors and values. The rarest variants are those with different colors or printing errors, which are particularly sought after by collectors.

3. **Stamps of the 1880s**: During this decade, several stamps featuring the portrait of Leopold II were issued, often with more sophisticated engravings and more detailed designs. Special editions or limited editions from this period are highly sought after.

4. **Postage Stamp of 1893**: This stamp is famous for its intricate design and high quality of printing. It shows Leopold II in a stately profile and was issued in a limited edition, making it a valuable addition to any collection.

5. **Stamps of 1897**: At the end of the 19th century, stamps were released in honor of the 25th anniversary of Leopold II's accession to the throne. These anniversary stamps are extremely rare and highly prized, especially if they are in pristine condition.

These stamps are important not only because of their historical value, but also because of their artistic design and the rarity of certain editions. Collections of these stamps can represent significant value, especially if they are well preserved and contain rare variants