This was helpful to me:
‘House of the Dragon’ refers to Old Valyria while including several characters from House Velaryon. What is the history and connection behind them?
www.distractify.com
Here's a little more:
Driftmark was settled by
House Velaryon prior to the arrival of
House Targaryen at
Dragonstone.
[3] Ships from Driftmark allowed the Velaryons to control the middle of the
narrow sea prior to
Aegon's Conquest.
[6]
Shortly after the death of her husband, King
Aenys I Targaryen, Queen
Alyssa Velaryon brought her children to
Castle Driftmark.
[7] When King
Maegor I Targaryen lay comatose after a
trial of seven, Alyssa proclaimed on Driftmark that her son, Prince
Aegon Targaryen, was the true king.
[7] After the
Poor Fellows were defeated by Maegor at the Great Fork of the
Blackwater, Alyssa and her Velaryon kin left Driftmark and submitted to Maegor in
King's Landing.
[7]
Many merchants traded at Driftmark instead of King's Landing to avoid the taxes of Lord
Edwell Celtigar, the
master of coin for King
Jaehaerys I Targaryen.
[5] When Ser
Lucamore Strong was disgraced from the
Kingsguard, his second wife and her children were sent to Driftmark to be fostered with Lord
Daemon Velaryon.
[8]
Because the ancestral castle Driftmark was damp and cramped, Lord
Corlys Velaryon constructed a new castle on the opposite side of the island to house the
Driftwood Throne:
High Tide, so-called because it was built on a tidal island only linked to Driftmark at low tide. As the island prospered from Lord Corlys's wealth, two large port towns grew on up the coasts of Driftmark:
Hull beneath Castle Driftmark and
Spicetown beneath High Tide.
[9] When King
Viserys I Targaryen brought his court to Driftmark for the funeral of Ser
Laenor Velaryon in
120 AC, the number of
dragons gathered on the island led Septon
Eustace to call it the new
Valyria.
[3]
The dragon
Sheepstealer was known for grabbing sheep from flocks in
Blackwater Bay from Driftmark to as far as the
Wendwater.
[10]
During the
Dance of the Dragons, Lord Corlys, the Sea Snake, launched
black ships from Hull and Spicetown to block access to Blackwater Bay. High Tide and Spicetown were burned in the
Battle in the Gullet, the latter so severely it was not rebuilt.
[10] Hugh Hammer and
Ulf White were given small lands on Driftmark after the
fall of King's Landing, but the two new knights felt they deserved greater rewards.
[11] Driftmark became hostile to Queen
Rhaenyra Targaryen after she imprisoned Corlys.
[12] Since Lord Corlys had not yet reconciled with the Queen Dowager
Alicent Hightower on behalf of her son, King
Aegon II Targaryen,
Alyn Velaryon prepared his
fleets at Driftmark to attack Aegon on Dragonstone. Conflict was avoided when Corlys was pardoned by Alicent.
[13]
Lord Corlys served as a regent for King
Aegon III Targaryen. After his death in the
Red Keep, Corlys's body was first sailed to Driftmark by
Marilda of Hull and Lord Alyn aboard
Mermaid's Kiss, then buried at sea near Dragonstone aboard
Sea Snake.
Daemion and
Daeron Velaryon reconciled with Lord Alyn in return for lands on Driftmark.
[14] Lady
Baela Targaryen lived on Driftmark after wedding Alyn.
[15] After learning that Alyn Oakenfist was sailing to the
Sunset Sea to end
ironborn raiding,
Dalton Greyjoy,
Lord of the Iron Islands, desired to slay Alyn and then conquer Driftmark for himself. Dalton was slain by
Tess at
Faircastle, however.
[16]
